Yes, that system is overkill on almost every component. The Intel Extreme chips are a good way to burn money, as are SSDs and the GTX295s.
Only get them if you know you need them, and given that you are asking here, i would say that you don't know for certain that you need them.
For slightly less than half the price you could get the next i7 down(2.9Ghz) which will be plenty.
The other factor here is that you are using ArchiCAD 11, which will only ever use one of your CPU cores, so unless you are planning to upgrade versions soon, or are using Artlantis a lot, you are going to be getting terrible value for the huge pile of money you will have to put down for this thing.
Also, who is putting this together and overclocking it? Are you aware of the impact this will have on the lifespan of your system, not to mention that Intel won't give you any warranty on it?
The SSDs will make your system boot really fast, but will most likely not make any difference to ArchiCAD or Artlantis performance.
The GTX295s will make 3D games really fast, but will not speed up 3D generation times in ArchiCAD or Artlantis(although they will make OpenGL navigation nice and smooth).
Also, remember to only use Vista x64 Business or Ultimate.
Josh Osborne - Central Innovation
HP Zbook Studio G4 - Windows 10 Pro, Intel i7 7820HQ, 32Gb RAM, Quadro M1200