Your hard drive is good. Any hard drive will perform the same as the one you have. The only option is to get an SSD. But you don't need an SSD, since this rig will not need it. If you get an SSD the only difference you'll notice is shorter loading screens. If you want a slightly faster HDD then get the Western Digital Caviar Black that I suggested with costs around 200$ (Which is way off your budget.)
The motherboard is good. I picked the H77 chip set because you won't be using the Z77 chip sets overclocking features. Plus the H77 has the key features you'll need like USB 3.0, PCI E 3.0 ect. If you want you can use the
ASUS P8Z77-V LX. which is around the same price range.
Concerning the PSU. 750W is enough. People tend to overkill with PSU's for future upgrades. Plus older components use more power. For example the i 2500k uses up to 95W of power whereas the i5 3570k uses up to only 77W, or the GTX 570 uses around 150W of power whereas the GTX 670 uses only around 90 to 100W.
Note that you won't be overclocking the system. When overclocking a 95W CPU it can use up to 200W of power. Even for a graphics card, if it's 150W it can use up to 300 to 350 W (Especially if it's a high end card like yours).
Note that your system won't even use the fully 750W of power, it would only use up to 500W. You won't be even using the full 100% performance of the hardware because there is no game or program yet in existence that uses the full performance so you might be using even 300W instead of 500.
1200VA = 780W. If your TV uses up to 250W , that could leave you with 530W. But I still use a 1500VA (1050W) Just to be safe. You'r whole PC + TV should run about 5 to 10 minutes without power.
A GTX 560 (A very very slow card compared to the GTX 670) can play any game at 1080p. The size of the screen doesn't matter. You can use a 102" Screen that's 1920x1080 and still get the same performance as a 19" 1920x1080 screen. So you don't need to worry about facing
any problems in gaming. The only time you need to worry about a higher end card is when you're gonna game in 2 or 3 screens at the same time (Nvidia Surround).