I think ripping the relevant parts out of Satchmo will be a major
undertaking, because it's a very complete e-commerce solution, and it
would probably take quite some time to understand all the internals.
But letting yourself be inspired by Satchmo or LFS (Lightning Fast
Shop) is a very good idea.
Maybe this is also worth a look:
The project doesn't seem to be very active anymore, and I can't say
anything about how good it works, but it seems easily possible to
rewrite it for Pyramid.