All the speakers in the Bose system are powered from the bass module, not from the 'receiver', and Bose is extremely proprietary.
But, I believe that you can cut the ends off the speaker wires (RCA ends) strip them back, and plug them into any A/V receiver without issue. You can't use the bass module with your system, but you can pick up an inexpensive (and real) subwoofer to fill in the low end if that's the route you want to do.
After a quick Google search, I found this writeup which looks like it pretty much covers what you are looking to do:
Bose Cubes without Acoustimass connected to a non-Bose Amp - eCoustics.com
The response is far more critical, but I think that it is worth considering that at some point you will want to upgrade away from the Bose cubes to some serious speakers, and wire and plan accordingly. If you 'own' a place and want diminutive speakers, then in-wall speakers are really as unobtrusive as it gets and can be had for not a lot of cash.
