64bit really is designed for processes that REALLY require such bandwidth. the 32bit version is fine... i REALLY doubt a person, unless running a server, actually would require that much bandwidth... but then video editting comes to mind.
frankly, such a budget for such a mobo, would also require subsequent SCSI drives... which in itself costs a bundle...
anyway, HUGE budget required for such an undertaking despite the cost of the actual motherboard, which is nothing compared to the actual cost of the storage itself.