I'm using SnipCart to build an e-commerce site for a client with a small inventory.
I'm using a list and detail page with regular Perch. They don't need many variants at the moment so this meets their needs for now. I'll put it on github when it's done if it's useful for anyone.
It would be interesting to hear about what others have done, especially with Runway & SnipCart, for more complex solutions.