I am in the same boat as you and form your parts list your new pc will be near identical to mine, from my research your processor is bang on the ocin potential you wouldnt believe there are a couple of links on this site to reviews where they ran stable over-clocks at near normal voltage which will beat a vanilla FX55. For the ram it looks good but you might think about possibly a GB of GelL dual channel value stuff it costs about the same and from what ive been told it is better in the long run performance wise.
I looked at the motherboard you are getting but it came down to the gigabyte nf4 or the MSI one, i have pretty much decided on the MSI board it had some really nice featuresand good reviews and solid performance.
The gfx card i am getting an nvidia one as i am more familiar with them and have heard some horror stories about them lately which has put me right off. After reading alot of reviews i have decided to get what everyone seems to say is teh best of the 6600GTs the Gigabyte 128MB turbo with heatpipe i have yet to find a bad review of it and it has the bonus of being silent. It is cheaper than the one you plan on getting as well if my dollar pound conversion is right.