store credits

Hi,

I'm looking to set up two types of user points.

I.e.: Points and credits.

The reason for this, i want to use "credits" (userpoints) to let users buy credits throigh ubercart <--- possible
and pay for content <--- possible
(exchange the points to the content provider) <--- possible
who will be able to cashout his earned credits <--- another thing that i'm not sure of if possibe).

Also i want to have general points to rank users based on actions on the site (comments, fill in profile fields etc) <--- this i know is possible.