Tony,
I'd be very interested in finding out what features you feel are missing from NB_Store. In January we are planning on creating a new roadmap for the next release and any input is welcome. Please have a look at NB_Store and then log any features you think are needed on the codplex disscussions, I can't promise we'll have the time to implement your requirements, but knowing what people require is always helpful when prioritizing features.
The nopCommerce is a nicely matured e-commerce system, I had a look at it before I started NB_Store and I felt that integrating it into DNN was a step that could cause a massive volume of work, which would need maintaining constantly. I therefore opted to create an e-commerce for DNN from a blank page, this gives me control over what my clients need. I use NB_store as my e-cmmerce solution and I am always looking to improve it.
Like Mitch says, creating an e-commerce system is an expensive project and your simply not going to get the support and feature sets from an open source solution (I am trying!!), because of the simple fact that when a client wants to pay my company for work, the clients needs come first, and NB_Store comes after, sometimes the two are compatible and NB_Store moves forward at a greater pace, but unfortunaty these situations are not as frequent as I would like.
As a last note to anyone reading this, please help NB_Store by give as much feedback as you can...all feedback is more than welcome, both good or bad...it's only by understanding issues and requirements that we can make the improvements needed to create a viable professional open source e-commerce system for DNN.
Regards,
Dave