Ok, before I order the parts I want to make sure they're compatable. I have an AMD CPU, AM2+ socket, Phenom X4. My motherboard's sockets are AM2+/AM2, and supports Phenom/Athelon 64/ sempron

Will the processor work with the motherboard? My question is really; is Phenom X4 still Phenom? I think so since it's not Phenom II it should work right?

http://en.wikipedia.org/wiki/Socket_AM2+ You could always check wikipedia or google am2+ compatability, but yes phenom X4 work in AM2+ slots but its important for your motherboard to support the processor, its like even if a key fits into a lock doesnt mean its the right key for said lock, you know?

AM2 uses HyperTransport 1.0
AM2+ uses HyperTransport 2.0
AM3 uses HyperTransport 3.0

All of them will fit together, and you can use any processor in any of them. The phenoms are all am2+, and most dual core athlons (brisbane/windsor) are am2. If you put an am2 processor in an am2+ motherboard, it will use HyperTransport 1.0. The same goes for am2+ processor in an am2 motherboard.

am3 will throw things for a loop, however, as I don't think you can use am3 processors in am2 sockets. The wikipedia article has more on this, and in any case, you don't really want to mix and match.

Finally, get the deneb. Much much better than the agena, with much lower temps and thus requires less power. Not to mention phenom 2 finally beats out the q6600 in price/performance.

I think it was the other way around, that AM3 boards only support AM3 processors, but AM2/AM2+ boards support AM3 processors. So with AM3 the processors are backward compatible, but the motherboards are not.