Well the motherboards don't improve the performance of anything really... they just have extra features or more slots and can generally handle more power being forced into the CPU and GPU. If you do not overclock though these boards are highly superfluous. If you check benchmarks they actually tend to score slightly lower overall than their less feature rich counterparts.
Sooo, if you don't OC I would suggest pouring a little more $$$ into the processor for this one http://www.newegg.com/Product/Product.aspx?Item=N82E16819115224&cm_re=core_i7_bloomfield-_-19-115-224-_-Product
A motherboard like this should be more than enough http://www.newegg.com/Product/Product.aspx?Item=N82E16813128456&cm_re=gigabyte_1366-_-13-128-456-_-Product
Again, unless you need a specific feature the other motherboards offer the same performance unless you are really into modding.
The RAM is also a place where people waste money. The actual frequency of the RAM has to do with your multiplier and a bunch of other things, so in many instances more expensive ram, unless tweaked properly, doesn't run any faster than the more generic kinds. Eg my DDR 2 ram right now runs at a dumb 882 or something, but they are 1066 chips... they can GO UP to 1066 without frying but I can't use it as it is not stable with my processor at 4.1ghz... so don't go spending crazy money on RAM either.