Great question — answering as the UphillTech team:
Don't know much about SSNet but here's my take on the other two (that i can remember on top of my head :) nopcommerce - this is very easy to setup. it's extensible bec of support for adding pluggable components/features. MVC music store - might be too basic for your needs. Again these are just my thoughts as well based on what you describe for your requirements. Hope it helps. Good luck!
Full answer by alltej: https://stackoverflow.stackexchange.com/a/37007094 (CC BY-SA 4.0).
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