if you're going to get a new rear axle, leave the front 6 lug and get a toyota rear end from an 87 or later ifs toy truck. the width will match, it's 6 on 5.5 bolt circle, and the axle is plenty strong. you should be able to find one for a couple bills.

i'm going to run the waggy offset 44 rear(same as yours) with a centered t-case output. the offset is only about 4". i've stretched the rear 10" but with the dual t-case setup in mine, our rear driveshaft lengths will still be comparable. i don't see a problem with it. unfortunately, i won't be finished for a while so i can't tell you that it works. i've seen a few jeeps with the offset waggy 44/dana 300 combo. they've all been custom applications like buggies and such but i'm willing to try it to save a few bucks. worst case scenario for me is buying a very expensive driveshaft if i have problems with the OE style.

a good way for you to get a couple extra inches of driveshaft length is to run waggy front leafs in the rear. they're offset 2" and they're 2 1/2" wide. they're a little longer than yj/cj springs but you can unbolt the rear shackle hanger and flip it 180 degrees and bolt it back up. the springs will fit fine. once again, i haven't done it but i would think you could trim the diamond plate pieces you're going to install on the back to fit tj rear flares. that should center your rear tire in the wheel well. it should look and perform great, give you 2" more rear driveshaft length, and it's cheap.

if you're doing soa for the first time, you will need to address spring wrap in the rear and steering up front. there is info all over the internet on soa conversions so solutions to problems won't be hard to find. it all costs money though.