Hello, a little late reply
I am working on this now, seems like this https://github.com/weex/oscommerce-bitcoin might still work with some tweaks.
People should have their own wallets and preferably rely on their own nodes, however, this might not be feasible in today's blockchain size. BTC has grown to 360 GB, and Bitcoin cash BCH is 180 GB.
It would make sense to have a community-driven wallet, payment module. With solid nodes backend that can be trusted.
This makes sense as we see explosive growth in Bitcoin's two dominant flavors.