PSU confusion: 680i sli board+e8400 C2D

Whats goin on everyone, im havin a problem figuring out what to do with my power supply and am wondering if n e one could give me advice. Im in the process of building a new computer and just bought an eVGA 680i SLI board and E8400 C2D CPU (the 45nm one). I currently have a 450w power supply in my old rig, but am almost positive this will not be sufficient for these new parts. If this is the case, i want to spend around $100-$150 on a nice PSU. Does anyone have any suggestions on how many watts i would need or what PSU's provide reliable, stable power? I am also planning on overclocking if that helps.

Specs:
eVGA nForce 680i SLI 775 A1
E8400 45nm
(2x) geforce 6600 GT (yes, i know these suck, working on putting money together for (2x) XFX 8600GT XXX edition cards)
2gb Corsair 800 mem

Do yourself a favor and don't do SLI with crappy cards. The 8600GT is a fine card for playing Solitaire and movies and Diablo 2, but a very bad choice for SLI. Get a single 8800 GTS G92 512 MB, it will humiliate the 8600GT SLI. Plus this way you get to add a second one (now, or later).

PSU: PC Power & Cooling Silencer 610W would be perfect. Maybe the 750W version, to leave more room for adding disks and lights and so on. Corsair 620HX would also be a fine choice.

Some more here:
http://www.tomswiki.com/page/Tiered+PSU+Listings

Edit: I read a review that showed the E8500 OCing much better than the E8400.

great info guys thanks a lot, wound up ordering the PC power 750w. I think ill take your advice with the graphics card too...friggin expensive tho! maybe ill wait til the 9600gt comes out and then get the 8800gts cheap...but then of course id be buying yet another obsolete part...gotta love ongoing tech advancements.