Multidomain and ecommerce

Which plugins should I use for the following:

I am using the membership/multisite/buddypress/affiliate/marketpress plugins on BetterWorldPrograms.com

I want the ecommerce store BWCOL.com to be on a separate domain from the main community domain.

Do I install marketpress on the main domain Betterworldprograms.com, or on the separate ecommerce domain BWCOL? Which plugins do I use and where?

I want members of the main community to be able to access the ecommerce site. However, there may also be times I want people who are not members of Betterworldprograms to be able to get to the ecommerce site.