I wouldn't think a center coil would hurt articulation at all.

For another option, you might be able to find some air shocks to fit the rear. That would give you easy height adjustablity. If you leave the air shocks cross-linked they will help articulation.

93 4X4 ext-cab, auto, SR5, 3.4 V6, supercharged, 2.1" pulley, URD fuel mods, Aquamist WI, IPT valve body mod, dual cases, 4" superlift, Alcan springs, 33 BFG MT, ARB locked front & rear, 5.29 US Gears, RB 1" BL, 1.5" BJ spacers, TJM T-17, Warn m8000.