None of the guys I wheel with run anything other than the 63's and standard shackles, and have more than enough flex/articulation, and that is with running 37's. I wouldn't spend the money on Jonny joints now, you probably wont need them.

More than tread lightly. Leave it like you were never there, nor anyone else.
'90 X-cab 4.88's 33 BFG AT's, rr ARB, Headers, Ignition upgrade, cold air induction.
'91 X-cab 5.29's 315's BFG MT's, rr ARB, custom bumper and flatbed