My suggestions would be to ditch that memory and ditch that graphics card. None of them are worth buying at those prices. Some better alternatives:
Memory:
Kingston HyperX 8GB (2x4GB) DDR3-1600: $40
Graphics card:
HIS iCooler Radeon HD 7770 GE: $120/$105 with MIR.
Corsair Vengeance is okay memory, but it's certainly nowhere near the best. In terms of reliability you can't beat Kingston, and despite the 1.65V rating the memory runs fine at 1.60V. For $40, it can't be beat.
As for the graphics card, the HD 7770 is significantly more powerful than the 550 Ti and consumes less power to boot. For just $5 more, you're getting a lot higher frame rates.
As for the motherboard, this depends on what features you want. Considering the fact that you won't get a high-end graphics card, I don't think CrossFire/SLI is too feasible an option. What I'd recommend if you want to get a ton of features at a low price is to get an
ASRock Z75 Pro3. It's basically 99% the same as the Z77 Pro3 but with a lower price. It has great reviews, too.