I overlooked the fact that the shopping cart I list above was an ASP solution - something I won't be running on my Neptune server anytime soon
So after looking in the Zen and OSCOmmerce carts, it seems that both can do digital downloads, and both seem to be pretty good solutions.
Is there a crowd favorite or recommended choice for what I'm trying to do with anyone that has maybe done a digital download web site?
Here is the current site: drumsondemand.com (hosted still at my old reseller plan - so no jokes about that yet!)
Thanks!
Scott