Everything looks pretty good, if you wanted to save a few bucks I would go with an E6400 and OC it a little. Take what you saved and buy a after market HSF and once OCed it will out perform the E6600 and be cheaper, right now my E6400 OCed will out perform a E6600 stock easy. (OCing these cpu's are really easy.)
The PhysX cards are not really worth it at the moment unless you have a lot of money to burn.
As far as PSU's, I would recommend this one.
http://www.newegg.com/Product/Produc...82E16817151031
As far as SLI, I don't think its a worth while investment considering you never get double the performance so why pay double the price?
As far as motherboards, I like the asus commando, SLI support and an OC machine. If you OC it don't worry about the FSB, mine currently on this rig is 1600 FSB, so no need to worry there.
http://www.newegg.com/Product/Produc...82E16813131149
For memory I would recommend XMS2 series (Corsair). Performs well and OC's like a champ if yous o choose.
edit: if you are getting liquid cooling you better be OCing! :-)
edit: and why only an 80 gig HD?
edit: and please buy a better case, seriously....