a few details from me on my system?
This is what I would recommend for $900
P4 2.6C ----- $175 (retail w/HSF)
ABit IS-7 ----- $89
GeilDDR433 - $124 (2x256) (2x$62)
VGA fx5900-- $230
40GB WD 8mb-$68
48x24x48x16- $55 (liteon CDRW-DVD combo drive)
Asipre Turbo - $52 (cool case w/350W PSU, window & temp probe display)
Win XP home - $98
shipping ------ $15
TOTAL $906 (all prices from Newegg.com )
I guarantee that system would clock to 3Ghz 100%
probably about 90% chance of 3.25Ghz...
and to get higher you would probably need a better HSF and/or a bit of luck.
The system I was talking about was cheaper b/c I was going to put a ti4200 in it for $96, so it would have been under $800.