BuddyPress Modifications

I was able to find a solution to my CKEditor issue, but will have some other tweaking that I would like done. Please modify your bids (if necessary) for the following work: I would like a consult on the best set-up for a set of BuddyPress powered sites. The sites will be similar, but not the same, and the users in one site don't need to be able to see the activities of anyone in parallel sites. (This may be a desired function in the future, but not now.) I am starting with one site, but plan to have several of the same type of site running if the first works out well. I need a solution for speeding up my site(s) as well as preparing it for being easily scaled up. I need a unified search feature like "BuddyPress Global Unified search" - this would be ok with a bit of modification. I also need a quick fix that would restrict site registration by email domain. Currently I am using BuddyPress with the Membership plugin by [login to view URL] as the main parts of my site. Winner must sign NDA.