i'm planning on buying bf goodrich all-terrain t/a ko 315/75-16 tires (34.7" diameter) for my 2002 xterra se s/c. can someone recommend the optimum body and suspension lifts i should be using (i.e., how much of a lift will i need, and what brand to look for?) thanks!

You pretty much have to get a 3" Suspension and 2" body lift. There is tons of information on lifts in the the Mods/Exterior section (here). Don't forget to pick up a replacement steering system while you've got the credit card out. :D

Are you keeping stock gearing with those meats?