Bill,

I think you'll find it hard to go past CATAlooK as a paid-for solution. It is a very powerful and feature rich product at a very reasonable price. I've now used it for about half a dozen customers and they are all pleased with it.  My only caveat would be that since it has so many configuration options it is rather daunting at first acquaintance, and may take you a while to get set up as you want. The manual also leaves a little to be desired - it's not well laid out and has some interesting German-English translations :). So it may not be the best choice if you want a system up and running quickly. If you do need a rapid implemetation then the new version 2 of the DNN Store project module seems to work well enough in my limited experience with it.

Regards,

Graham