stock rear springs are fine, 90/10s and 4 cyl springs will work ok if you don't want to buy something like a moroso trick spring, etc.
spend some money on some LCA's at least and have your pinion angle set/checked.

my susp. was pretty basic (LCA's, single adj UCA's, 50/50's in the rear, 90/10's in the front with coil overs).
best 60' i cut was 1.29.. (although i might've been making a little more power than you are now).

you don't want it to squat.