I would suggest you get the i5 2500k instead. Their performance difference is very minimal. If your not set on it, get the the i5 3570k. You'll take advantage of PCI Express 3.0 for your GPU.
16Gb RAM is too much for gaming. The performance difference is only noticeable if you're doing things like video rendering and such.
I intend to overclock and figured I would get the i5-2550k because I didn't need a graphics card. However, as azeem40 mentioned, there could be a use for the integrated graphics card for trouble shooting.
Despite that though, I thought there were cooling issues with the IB chips. Would I still be able to get the OC performance out of the i5-3750k that I would out of an i5-25xxk?