I'd get an ASUS P7P55D-E Pro instead of the ASRock, any HD 5770 over a GTX 260 (relatively similar performance, GTX 260 slightly faster in some games, but HD 5770 = DX11, Eyefinity, lower power consumption and is cheaper), also I'd get a Samsung Spinpoint F3 500GB or WD Caviar Black 640GB. As for the RAM, thats a triple channel, and Core i7 800 Lynnfields can only use it in dual channel, so get a 4GB kit instead, unless you do need 8GB. Apparently some LG GH drives have some firmware which comes with some random annoying adware, I'm not sure. If you get the HD 5770 instead, that PSU is fine - if you want the GTX 260, then you probably need a Corsair HX650W.
Recap of recommendations:
Motherboard - ASUS P7P55D-E Pro
Graphics Card - HD 5770
HDD - Samsung Spinpoint F3/WD Caviar Black
RAM - Dual channel 4GB/8GB kit.
Optical Drive - Something not LG GH, not sure though.
PSU - Corsair HX650W if you do want GTX 260, otherwise TX650W is good for two HD 5770s.
1) A single 5770 would be good enough for most games maxed out at 1600 X 900 resolutions or similar.
If you are planning on a full HD, ie 1900X1200, the the 5770 would be inadequate for games like Battlefield BC2, Metro 2033, not to mention the upcoming Crysis 2. Here, a crossfire 5770 setup would work great. If you can, go for a single 5850, which comfortably plays all games at full HD.
2) The Arctic cooling freezer is a good hsf. I think you can get around 3.6 - 3.8 GHz, while keeping the cpu temps under 50-55 C.