holy crap! push you i7 920 to 3.2? no way thats an insane oc d00d!! lol you'll go WAY past 3.2.
from the looks of it, your buying in canada if you shopping at newegg.ca, shop at NCIX.com, they price match anyone and it's cheaper than newegg.ca by a good bit (after you figure in shipping, taxes, boarder fee, crap like that)
your build looks good, for god sakes don't skimp on the power supply, the one you have would work fine but if your looking at 750W ones, take a look at PC P&C silencer 750. it can be had for around $105 when it goes on sale (which is alot)
The TRUE would be better than the U12P but they are pretty close. everything else looks good.
I am completely willing to put the dual 4850's in instead of the 4870's. Also, I have the option of grabbing a 22 inch LCD monitor from my brother (a viewsonic), so I will eventually be having higher resolution. I would much rather stick it out with the i7 than run with AMD, but is there anywhere else I could cheapen (HDD, casing, etc.)?