only the t/c and front lower arm bushings are in 3 pieces since those are usually the ones people do more commonly.

im about to get the full kit, plus some steering rack bushings..if you're not going to do heim jointed baller adjustable arms these are the way to go. i'm fed up with the slop and stuff.

while you're at it, i would definitely recommend getting some steering rack bushings, they're like $20 or less and take 10 minutes to install.

and i'd look into some ball joint replacements while it's all apart. moog makes oem replacements for the front (pdmracing.com or enjuku/insert local shop could get them).

for the rear ball joints, nissan only sells the rear lower arm/ball joint as a single unit, so it's not worth it, but you can buy 91-94 b13 sentra ball joints. they are 1mm bigger, but they press in with no problems and work fantastic.

since you'll be getting all the press work done, i'd surely do those. i've felt the difference on older chassis' and it's pretty nice for the money.