I read that some mix (can't remember if it's front or rear) of grand wagoneer springs are the same as YJ's, but don't know about spring perch width. I'm sure if you could find dual waggy 44's you'd be happy about it. There are tons of them around here, still driving and everything, but it's arizona, and anything under 50 years old will probably still run after sitting around for that long, haha.
And yeah, isuzu rodeo 44's are also SUA (pretty sure), can have disks, and commonly come with 4.10.
What I'm thinking for my XJ is pulling another Xj 44, pulling outers from a ZJ for disks, and trying to find a rodeo with 4.56 gears and carrier... At any rate I'd probably end up with two or more 44's and parts floating around.
MJ 44 would be a good find for you guys too...