Ouch!
The only system I had oc'd was an old PII 350 that I think I squeezed up to 500 or so...that was my previous system...this one I just replaced the chip and it works just fine...I prefer boards that take various cpu's where you can upgrade as needs require...haven't looked at Mobos for a while, but that's how I would approach a new system...if they still offer those options...
On a side note...there was an old server sitting in the computer lab at school...the instructor said it was donated by one of the staff...it's an old IBM system (RISC 6000 or something like that I think) and he gave it to one of the students free...
That system was probably worth $100,000-$250,000 when it was cutting edge...it's probably still a kick-a$$ machine and it works...but it's huge...took two of us to lift it into his trunk...takes four processors...has like four HDD bays, and I think he said had 2 gigs of RAM (IBM proprietary of course)...