both are same. 550 is a BE.
but none of them is good. the best in that range is AMD Athlon II x4 640 @ 4.6k
---------- Post added at 06:37 PM ---------- Previous post was at 06:36 PM ----------
for mobo look at - Gigabyte GA-880GA-UD3H @ 5.5k
which case and power supply you have? and you have ddr3 ram?