General question about Visual Composer

I am installing the Preview NW2004s, including VC, so this is very new to me.

I have no SAP system, but I am asked to make an application which later needs some integration with SAP R/3.

The application is currently written in .Net with SQL or Oracle as database. But I want completely rewrite it, to make it available as an SAP Portal Application.

I have already done some exercises with Dynpro and JavaBeans, and now want to see if Visual Composer can be of any help.

Can I use my existing SqlServer Db with the Sneak preview version? Or is it necessary to convert to MaxDB?