Right off the bat, drop down to an i5-2500K. The 2600K will take up too much of your budget and the performance increase in gaming wouldn't be worth it for the price.
For Mobo's the ASRock one you listed is the one I'd recommend. It's fairly cheap, a good performer, and is PCI-e 3.0 compatible which will be good if you decide to upgrade in the future.
For that budget range, either an AMD 6950 or a GTX 560ti will provide the best bang for buck in gaming.
For PSUs you should get something from Seasonic, Antec, Corsair, or PC Power & Cooling. Those guys make the best power supplies and that is not an area where you want to skimp. A solid 650W or higher would work.
For a case, Anandtech just did a review on the
Antect Three Hundred Two and it looks like a pretty good case for a reasonable price.
For Ram, an 8GB (2 x 4gb) 1600Mhz kit from G.Skill or Corsair will serve you well.
You'll also need a hard drive and an operating system. For hard drives, I'd recommend buying the lowest capacity you can stand right now and upgrading later. The flooding in Thailand has caused a huge spike in HD prices.