A 6.8L with 4.10's or 4.30's (not sure if these were ever offered back then) or the 6.2L with 4.30's or even lower (I'll have to look to see whats offered).
I'd steer clear of 3.73's as with 34" tires mounted I doubt that 5th or 6th would get used much (if at all). My 97' has 4.10's or 4.12's.
In "the valley" without a headwind I'll hit 4th until any rolling hill or the wind picks up, then its 3rd. Real hills/passes I'll always end up in 2nd at 40mph - you can almost watch the fuel gauge moving while "humming" along in 2nd. Not very relaxing. (and everyone on earth trying to get around you like the plauge!)
On the 4 speed the drop from 3rd to 2nd is rather harsh.
I may just "cheap out" and invest some time+cash on fixing the handful of "issues" that my 97' is currently suffering from. After all - its paid for. :)