You have 2 choices. Spend $300 for quality air cooling for the CPU/NB/SB and both GPUs, and putting high CFM fans all over the case. Noise, yes, not a quiet setup, but better than the stock fans on the GPUs. Your temps will be better, but not best.
Look at Thermalright parts for the CPU/NB/GPUs. I used them before I went WC, top notch.
WC for that setup, using quality parts will be about $700+. And take the + meaning probably more. Two pumps, rads, res etc etc.
Going quality Air, especially with Thermalright and a GREAT CASE is viable, but not good as water. Water costs a lot more, lots harder to setup, some extra maintenance, a PC Hardware geek loves WC.
Here is my standard WC noob cut n paste, please no offense, but it is another totally different way of thinking.
I'll steer you to some more technical links, please spend a few days (DAYS) reading posts, searching, learning. Don't forget to look for your case with WC. Gogole your case and the word watercool. WC stuff is larger than you think, I knowfrom experiance. WC setups done right are awesome and almost silent.
Great place, not wayyy over the top with uber WC guys.
http://www.ocforums.com/index.php
Uber place, owned by one of the worls winning OC guys in the world. Not a place to post or ask questions by noobs, but an awesome place to learn.
http://www.xtremesystems.org/forums/
Another good place to learn
http://www.overclock.net/water-cooling/
The GURU of independant testing, worshipped by many.
http://www.martinsliquidlab.com/
Great places to buy WC stuff
http://www.dangerden.com/index.php [...] e&Itemid=1
http://www.petrastechshop.com/
http://www.jab-tech.com/
Hope it helps, see ya in a few days, get edumacated!