For the speakers, search Amazon for NXG Pro 4.1. As for wiring up four speakers to two outputs, you really ought to have a four channel amp or multichannel receiver.
Strictly speaking, what you want might be possible by wiring both lefts in series, and likewise with both rights. That's as much as I'll say on the matter, though, as you really ought to put some effort into searching, reading, researching, and learning. I say that not to belittle, but to ensure that you understand fully what you're asking, how different wiring methods affect the load on your stereo receiver, and so you'll understand the risks and be careful not to make a mistake.
But research or not, I still recommend getting a receiver capable of driving four speakers natively without wiring hackery.
This Denon receiver would work just fine, plus offer expandability if you'd like to add a subwoofer and center channel later.