344213 Digital Goods Add On

I have the EZ Membership Script by Frank Salinas and I want to add a digital goods area to the site. So that each membership level, free, pro, and platinum each have their own membership area. I either want where the higher level can see all three, the middle level can only see theirs and the free member downloads and the free members only see the free member downloads. Or, I want where all levels can see everything, but can only download what is in their actual level and below.