Hey guys so I have some questions. This is my old pc

http://h20000.www2.hp.com/bizsupport/Tec...Id=3550541

I have replaced the power supply and the heatsink and the GPU. However, the 2.6 cpu is really old and 3gb of ram is not enough.

So if I were to get a new motherboard + cpu, what do i need to look out for ? Would any mobo work ? When hooked up to my hard drive and all of that, would I just be able to boot into the same setup that I had before (same OS with all my files and everything as it was)?

i'm looking at these

http://www.ebay.com/itm/New-AMD-FX-4100-...5af329bf9a

http://www.ebay.com/itm/NEW-AMD-A6-5400K...51a44f8d5f

http://www.ebay.com/itm/COMBO-AMD-FX-410...19dec22a4e