what processor do you want to install.
then we can decide what board you need
Intel Core i7 860 Quad Core
if you want to for that you have no option but to go for tripple channel memory - ddr 3.
ddr 3 is as good as reliability of ddr 2 its just that some motherboards dont work well with it ( msi x58 pro -e if you have larger than 6gb for example ).
the i860 is a good chip, AM3 will go to 6 core soon as i assume socket 1156 will go to but it may need a new chipset...
1336 will be core upgradable.
I personally would go for a 955 on a AM3 platform with ddr3 and wait for the 6 core chip to come out, that way youve got upgradability..