Setting up a new install for BuddyPress from vB4

Hi guys,

I have an existing (though not yet busy) vBulletin 4 forum, utilizing the vB CMS and User Blog features. Only a handful of users, posts, and blogs so far. I'm pretty sick of trying to get vBulletin to work the way I want it to, and I'd like to try BuddyPress instead.
Here's how I want it structured:
Homepage is, with the official LP blog.
Subdomains are user blogs, ie would be my travel blog.
Each user can participate in a central forum somewhat like vBulletin, phpBB, etc.
Other features on the main site (store, chat, public photo albums) are centrally located and accessible by all users in the network.

From what I understand about WP MultiSite, BuddyPress, and ProSites, I should be able to do this. I am looking for a bit more specific guidance as to where to start.
I expect that this should be a separate WP install from my existing JLW network for my freelance sites, right? Also, any information about migrating user/site/blog/cms content from vB4 to WP and BP would be appreciated!

Thanks for your help everyone.

Current Site for Reference:
User Blogs