Dude, no offense here but you have no idea what you're doing and you want to open membership sites and attract affiliates to promote them?
Other than NATS there is MPA3, very good software.
http://www.mpa3.com/
Instead of Carma you should use Elevatedx. Many people love it!
http://www.elevatedx.com/
Main page/tour pages can be static yes, many sites still are. If you want them to change via a script usually the CMS does it. (I believe elevatedx has that option, not sure) And you can build static and change to the script later if you want to of course.
Your payment processor will link that or the NATS or MPA people will do that. Likely you will need to hire a programmer at least to set that up if you need it.