This is actually a fine setup for gaming, with a couple minor issues. First of all, the RAM you chose is slow by today's standards. Most gaming rigs, will have 1600MHz or greater RAM, or at the very least 1333. Your's is only 1066. The performance difference isn't monumental, but there definitely is one, especially with demanding games. I'd recommend an 8GB kit from G.Skill like this one
. The 560Ti is a very good gaming card, but you'll want to go for a bigger power supply to be safe, especially with an FX proc. Something in the 500-600 Watt range would be best. The CPU and motherboard are just fine, and I used an Antec 300 myself for a build a while back -- fantastic case. You don't need a hard drive mounting bracket for that hard drive, the case will accommodate it just fine.