I'd have a look at
Actinic Catalogue. It has been around for years. I built an Actinic site about 6 years ago when one of my clients was given a free copy of the software by Business Link. It was pretty easy to set up, even then, although it was almost all JavaScript driven. Nothing came of it as he decided not to sell on-line as he could not spare the time to deal with the orders!. The program looks a lot better now, and can handle a good selection of payment gateways.
Personally I use VirtueMart now for e-Commerce sites, but remain open-minded about other solutions.