So sorry for the delay in the reply.
We were buzzy with billable support.
The answer is given in previous post
/en/forum/28-pre-sales-questions/12228-enquiry
Concerning the support level, you have the free support via this forum where we answer when we have the time.
You also have billable support that can be ordered at
/en/joomla-multisite?page=shop.product_details&flypage=flypage_multisites.tpl&product_id=35&category_id=1
When proceeding with billable support, we are using Skype for the chat and phone.
We are also using the
www.teamviewer.com application to share our desktop during the support session.