You are stwitching from a old phenom X6 to another phenom X6... Not really an upgrade over your old CPU... currently, phenom are still the better that AMD has to offer, but a little outdated, 3-4 year ago, it was a real beast, but today, for a little more, you get lot better performance with intel. go either with a i3, or if you can, I really recommend i5-3570k. Cost 100$ more than than phenom, but more than twice the performance. More recent, so better technology, smaller dice, very easy to overclock, and can overclock more than a phenom. For a motherboard, good choice to take gigabyte, cheap, and get good performance. Currently, what i recommend, its either Asrock, gigabyte, or Asus. The extreme serie from Asrock is pretty good.
Asrock:I recommend either
extreme4 if you are on a budget, or if you can, go with a
extreme6 or a
Fatal1ty professional.
Gigabyte: For gigabyte, I recommend the
D3H if you are really on a strict budget, or if you can spare 20$ more, go with the
UD3H. And if you need something big (not in size, but in feature) take the UD5H, lot of sata port and 3X prci-E 3. And if money don't bother you too much, you can take a
sniper
Asus: The sabertooth is a good choice, and also the maximus. If you need something very stable, and you can afford, go with the
deluxe, but else, i recommend maximus overall for the price and feature it offer.
For RAM, take 4X4 GB or 2X8GB. If you want your pc to last you many year, 16 GB is the recommended. 4 GB was good 8 year ago, 8 GB was the choice like 4-3 year ago until now, but currently, 16 GB is cheap, because its more common to see that in computer. Although, I don't recommend to go with 32GB, don't worth it, cost too much. You get 16GB of memory at the same price 8 GB was 3 year ago. 1800 mhz memory is good, and cheap, but you can also go with some overclocked one at 2100 mhz. But don't waste to much to get more overclocked, you wont see really difference, or very very minimal difference between 2100mhz and 2600 mhz. For memory, I recommand G.Skill or Corsair.
For video card, if you followed my advice with the motehrboard and the processor, you can take pcie-express 3 video card. Go with a ATI readon 7xxx or Nvidia serie GTX 6xx.
If you plan to overclock, you can get a good water cooling for 60-100 $, corsair H60 or H80 or H100.