First off don't bother with 2 raptors. Youd be much better off either getting 1 raptor + 1 large storage hdd or 2 higher storage hdd in a raid for teh same price.
If you arent getting a 64 bit os, then don't bother with 4 gigs of ram. You won't be able to make full use of all 4 gigs with a 32 bit os.
The killer NIC is a nice card but most reviews show it gives a negligable performance increase if any. You could save the extra cash and probably not miss anything without it.
The psu is probably more than you need, though it does give you alot of headroom for upgrades. If you aren't planning on going sli at any time in the near future you could probably save another hundred or 2 by going with a smaller and cheaper (not cheap) psu.
As for cooling most people will tell you to go with the big 3. Zalman, Tuniq or Scythe. I'm not sure how good that liquid setup is, but in general most pre-bulit sets are iffy.
As previously said, you don't need both raptors, you'd be better off getting one raptor and another drive with a lot of space (although if you want the best performance, then getting two raptors in raid 0 would be best). You don't need Killer, in my opinion it's not worth it's price. If I were you I wouldn't go with the E6700 either, I would go with the E6600 because you can EASILY achieve e6700 speeds with an E6600, yet there's around a $200 difference. Furthermore, it looks like you have a very good system here, should last you for a while and pave your way for a quad core upgrade soon.