A good motherboard to unlock all 4 cores of AMD Phenom II 555 with?

[CrazyTurkishBoy]

Hey guys, I've selected the AMD Phenom II x2 3.2 gHz 555BE processor for my build. I was going to go with the the 955, only to learn that the 555 is almost the same thing, except 2 cores are not used. I heard that some motherboards won't do it well or something, and I was wondering if there was a good motherboard UNDER $70, that can support this, DDR3 RAM, onboard sound, onboard Wi-fi, and either ATX or microATX.

Another question I has was is it better to have 2x2GB RAM, or 1x4GB? I know it differs from motherboard, so if you could tell me an answer based on the motherboard you chose for my first question, it would be appreciated.

Thanks

 

[CrazyTurkishBoy]

I meant unlock all 4 cores when I said it lol