Will this rig be used primarily as a gaming rig? If so, you're investing money in the wrong areas.
1) I would recommend swapping out the Intel Core i7 3770 for an Intel Core i5 3570k. The 'k' in the model number will allow you to overclock Also, Hyperthreading has no real benefits in terms of gaming so it's best to save that extra ~$100 or so and invest the money elsewhere.
2) Swap out your GPU. The 550 Ti is not a bad card by any stretch, however, there are LOTS of better options out there at the moment for the money. For $200, you could have a massive leap in performance.
I would recommend the GTX660, Radeon HD7850, Radeon HD7870, or the Radeon HD7950 ($300).