first.... keep the post short and sweet. take out any garbage we do not need to see, it makes it much easier on us who have to try and comment.
COOLER MASTER HAF 922 RC-922M-KKN3-GP Black Steel Plastic and Mesh Bezel ATX Mid Tower Computer Case with USB 3.0 and Black Interior
***your choice. the haf is a pretty common case with mostly good reviews if i remember.
SAMSUNG Spinpoint F3 HD103SJ 1TB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive
***this is one of the three drives most often picked as a data drive so i would say you are good. an alternative would be caviar blacks.
EVGA 01G-P3-1561-AR GeForce GTX 560 Ti FPB (Fermi) 1GB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready SLI Support FPB Video Card
***not sure what the Ti suffix is for but i do agree with a GTX card over a GT card. normally what i like to do is get the best card in my budget which is normally one or two steps down from the bleeding edge. any mid level and above card should hold out for at least a few years.
LITE-ON Black SATA DVD-ROM Drive Model iHDS118-04
***no comment, anything will work.
CORSAIR Enthusiast Series TX750 V2 750W ATX12V v2.31/ EPS12V v2.92 80 PLUS BRONZE Certified Active PFC High Performance Power Supply
***i've had good luck with my corsair psu. 750 is probably more than enough but do a power calculation of your max loads + 15 to 20% and compare to this output. there are free websites for this. make sure that this also has the right mb main power plug arrangement, enough aux power plugs for the mb and enough gpu power plugs
G.SKILL Ripjaws Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-12800CL9D-8GBRL
***double check your motherboard for what type of ram setup it has. dual channel, triple channel or quad channel. dual= 2 or 4 sticks triple = 3 or 6 sticks quad = 4 or 8 sticks.
ASUS P8Z68-V PRO/GEN3 LGA 1155 Intel Z68 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard with UEFI BIOS
***just make sure it has the features you want. does it have integrated audio which you will need since you have no soundcard picked out.
Intel Core i5-3570K Ivy Bridge 3.4GHz (3.8GHz Turbo) LGA 1155 77W Quad-Core Desktop Processor Intel HD Graphics 4000 BX80637I53570K
***an i5 should be okay for a budget gaming machine and is overclockable for the future. personally i pick nothing but the i7's but this depends on what you want to do with the machine.
COOLER MASTER Hyper 212 Plus RR-B10-212P-G1 "Heatpipe Direct Contact" Long Life Sleeve 120mm CPU Cooler Compatible Intel Core i5 & Intel Core i7
***unless you plan on overclocking you can use the stock cooler. in fact depending on how much this costs it might pay for the upgrade to i7 over i5 and you can just use the stock cooler.
what would speed your system up?
adding a small 80gb or larger ssd drive for boot. this would make your system as snappy as it should be. if you dont then your hdd will likely be your bottleneck. with a ssd the bottleneck might be your cpu instead.
upgrading to an i7 or better gpu might increase performance depending on what you plan on using it for. if you plan to game at 1080p then you are likely fine but if you want to game at higher resolutions then peformance drops off rather quick.