Visitor + Member Registration with Combined WP, Buddypress, Membership elements

I’m having trouble configuring the combined elements the way I’d like, and wondering if someone can help figure it out, or point me to documentation to configure things correctly.

I have the following elements that I’d like to work together:

JanRain sign-in

Wordpress

Buddypress

Membership

Optional: will also use Affiliates and MarketPress & would like to minimize multiple sign-ins there too.

I’ll have 3 user classes:

a) visitor – can access basic information on WP pages – about, service descriptions, etc.

b) free member – can access Buddypress, and additional WP pages

c) premium member – can access Buddypress and all WP pages, including premium discount codes, premium events and premium training.

What’s the best way to accomplish the following:

New visitor comes to site, pop-up displayed with links to “Join”

“Join” page includes options for

a) free member – join with either JanRain or email

b) premium member – join with either JanRain or email

Free member sign up also creates a Buddypress member, and provides access to defined WP pages

Premium member sign up also creates a Buddypress member and provides access to full set of WP pages

Thanks for taking a look, and I look forward to any advice.

Best,

Greg