Want To Lease Multisite subdomains

I’m not sure how to outfit a multisite where I want to lease, or rent, individual blogs which are already created for a particular subject. Kind of like a sponsorship type of thing where the user can add their own images, articles, video, community etc. for their particular subject.

So I am putting together 50 sites at a time (I will be creating a total of 800 subject-specific blogs), and am manually adding a first page with content that would be relevant to each blog’s title. On the front page of the blog is also a notice that the visitor can “own” that particular blog for a monthly/yearly fee with all the bells and whistles.

Which plugins would fit the above scenario best? I have been creating all of the sub-sites under my main site admin account.

Probably just like most folks when they first sign up for premium membership here – I have installed 75% of the available plugins into this site. Maybe overkill – but everything looks so good!

Thanks for any help or ideas on this…..