Now, I am sorry to say that I think you are confusing him ExSim.
I would go for a SuperMicro board. Then you can Intel, AMD, and Celeron to your hearts content. Anyway, Celeron is good, very good and few people would recognise that it has a 66mhz bus. It goes like stink and I am happy with mine. I've got a 533mhz and I honestly can't see why going any higher will change things dramatically. In fact when I changed from a 400 to 533 it took a while to realise that the REGISTRY is the master - and you MUST clean it up regularly. That was after 3 crashes. The clean boot did the trick and I haven't looked back.
Still you pays your money and you takes your choice!