1.- Joomla 3.0 Compatibily
2.- We want to create a commercial platform wich will have over 40 stores in different subdomains with hikashop.
2a.- Can we have one single cart for all the stores?
2b.- Can we chooese between single cart for all or individual carts?, i mean if some store does not want to have the same cart than other colud it be possible.
2c.- Single registration and single user for all the stores is avaible? and if in hikashop you need to insert the address and the client data is it possible to insert it in one place and share it between all the stores?
3.- What licence yo recommed us for this project.
4.- Waht modules you see necessary to achieve it?
5.- Do we need just hika bussiness or the other extensions too?.
6.- we choose templates from joomlart are them compatible with jms?.
7.- Thanks for ur time and hope well be working together very soon.

Fast response is needed to buy it or not as soon as possible

1) Yes JMS 1.3.x is compatible with Joomla 3.0 - See the Joomla logo with version on each product. This give you the list of Joomla version compatibility depending on the product.

2.a) Yes - As you can see we have recently published JMS 1.3.09 that include stuff for Hikashop and Hikamarket. Hikashop and Hikamarket have added new feature that make them "multisite".
See our change history
www.jms2win.com/en/faq/change-history-13x
Now you can create a super-store that see the product of plenty "mini-store" and in each "mini-store", you can setup the category to filter it on ONE specific website.
With Hikamarket multi-vendor, it is also possible to use the JMS Site ID to filter the vendor and make it only available on a specific website.

2.b) Yes and No. No because when you share Hikashop, this also share the users and the sessions. When working with website in different domains, apache (or IIS) does not share the session data. Under Joomla 2.5, the session are NOT shared automatically between subdomains. That mean that you can share the users but the session is not really shared. That mean that the user will have to re-login in the other subdomain or domain to get a new "session" data. As the shopping cart are generally saved in a session they will be automatically specific - except is you setup Joomla to decide sharing the session or use the "Single Sign-In for Doamins" that will result by a sesssion sharing.

2.c) When you share the Hikashop the users are automatically shared.
If you want that the users remain logged when changing of subdomains, you need a specific setup in Joomla 2.5. If you want the same for the domains, you need the "Single Sign-In for domains"
www.jms2win.com/en/joomla-multisite?page...51&category_id=1

When the hikashop is shared the address are identical in all the websites.
All the hikashop content is shared.

3) You can already start with JMS 1.3.09 basic.
Concerning Hikashop and Hikamarket, I suggest that you have a look on their website to see the difference between the starter, essential and business. Personnally, I think that essential is the minimum.

4) If you just need websites into subdomains, JMS 1.3.x is enough to start.

5) In addition of the Hikashop, see also the Hikamarket multi-vendor that may (not necessary your case) help you setup product for one specific vendor that is present in a specific website. With Hikashop, you can define a product that is present in several categories. As you can filter the categories depending on ONE website, you can have products present in a specific website. So that you can have a "super-store" inventory and "mini-store" with specific product.

6) Joomlart should be OK.
We have reported them some issue in the framework and if they have applied the fixes that we have provided to them, they should be OK.
In case of issue, report the issue to Joomlart that have the fixes.

We are also partner with Hikashop and have a close collaboration with their team to develop the extension with Multisites facilities in Hikashop and Hikamarket.
You can also use our partner link to let Hikashop know that you come from us.
www.hikashop.com?partner_id=16361

We finally bought hikashop bussiness and jms medium i think its fair for all of us.
I have to doubts now and they are urgent too as i should start the development as soon as possible.
1.- I think is better to have one store that contains all the products and little stores as a filter each one with their own cart and payment methods. As i have all the articles in the store i can set up the mai page to show related product or most sell product for the whole stores and my doubt is how should i configure that? should it be a single database or multiple?. As i told you all the stores will have their own subdomain. i´ve been watching the videos (not deeply) and i dont really know wich option to use. should be easy for you to guide me in this option.
We are using joomla 3, hikashop bussiness and plesk.
2.- if after you tell us the better way to proceed if we do not manage to achive the results needed can we contract 1 hour or 2 and you make the installation for us. I think if you tell me the best way to do the 1st point it would be not necessary but in case...how long will it take you more or less?

1) Concerning the number of DBs, this depend on the number of expected websites and the number of tables present in the DB for a single site.
The formula is the following.
Nb Site * Nb MySQL table per site * 3
MySQL consume 3 files per table.

Suppose that you consume 200 tables in the DB for a single website.
If you have 100 websites, this give 100 * 200 * 3 = 60,000 files in the same directory on the disk.
When you want to do the backup of the DB, this mean that you should have to lock 60,000 files on the disk.

You have to check (or customize) the maximum table that can be open by MySQL.
Pesonnally, I try to limit the number of files to 15,000 (or 25 websites into the same DB).

2) If you want that we install and setup your environment with a basic configuration, this generally require 3 hours of support. This consists in the installation of Joomla, installation of JMS and configuration of 2 or 3 websites to verify the symbolic link and DB sharing. On plesk, depending on the version and the hosting environment this may require more time due to specific plesk security constraint and in particular the "open_basedir" that is frequently enabled and require to update the server configuration. A root login will be required.

ok what i need to know now is can i install a general database with products and then, in each independent website, just the hikashop categories i want (each category would be a store) so the store should be able to manage just their products?.
In that case and what kind of installation of the ones you have in the tutorials should i use?

Yes you can create a super store where you create categories for each wesbite.
Once the slave site will be created, you can go in your super store and create the category for the new wesbite and also create products that will be displayed in this website.

The hikashop will be shared for all and the categories will be filtered on the particular website that you will have setup in the "super store".