Details about Membership & Prosites

Im getting ready to setup and configure membership and pro istes, but I am unclear as to how they work together.

Heres a quick backstory on how I want things to work so the comments below will make sense:

http://www.pictalo.com (prosite) will work as a prosite is expected to work.

– Pricing – $XXX Upfront and $XX a month

http://www.pro.pictalo.com Is a buddypress install. Members who sign up at pictalo.com are automatically signed up here (I have this already worked out.) Ideally, if someone isnt a member of pictalo.com, but wants to sign up here for a flat monthly subscription, they could do that.

THE QUESTIONS

I know with membership I can create the upfront pricing with finite/infinte subscriptions. My question is, do I install membership on the root or sub domain?

Does the above pricing model seem like it works with these two plugins?