Brake upgrade and wheel fitment question

Okay, so I've finally picked up the D44 I want in the back of my 98 XJ, and I want to upgrade the brakes before I drop it in. I'm looking at the ZJ disc swap and I just grabbed all the parts from the junkyard last week. Will the ZJ rotors and calipers fit inside my stock steel wheels? Also looking into the WJ front brake upgrade- what size wheel or backspacing is needed to fit those? Is there any other dual piston upgrade for the D30? If the D44 that I'm going to drop in isn't leaking from the axle seals, should I replace the seals and bearings anyway just because it's a 20 year old axle?

I have 15x10 inch steel wheels with 3.5 inch back spacing.

I installed the WJ conversion up front and put the ZJ brakes on the 8.25.

I used Teves calipers which are a lil bit smaller than the Akebonos. The Teves calipers are about 1/8" shy of rubbing my rim.

In the back I can stick my whole hand between the caliper and and rim. You should be ok even with stockers. I mean they use the same rims on the ZJ why wouldn't they.

I'll get better pictures of the Caliper in the front and the rear when I get home... I'm gunna wear this picture out! I need a different one!

Theres about 1/8" of room. It's tight but it fit.