Supporter - All I want is Access Levels

Useing Supporter for the Membership access only
I want to create a membership only website.

I want to give away the first 1,500 memberships, so I need a promo code system or just need to set the price to zero for now.

So all I really want supporter for is to grant access to most of the website besides the marketing pages. I don't want to offer templates or any of that stuff right now.

is Supporter the best thing for me to use. I will be using WPMU with the social theme and buddypress.