Keep the 20, one piece axles, maybe a
locker if you plan to wheel hard. If this is a weekend warrior, save your self the cash and skip the
locker, running with open diffs will not only be easier on your wallet, but will also let you learn how to wheel and hone your skills.
If memory server me, 82 was the last year for the narrow trac axles, you could look for a 86 CJ and swap in a D44 rear and the D30 front (same D30 you have just a little narrower) or get just the D44 rear and either cut the rear down or run spacers up front.
At this point, If your largest tire choice is 33"s, keep the modle 20! I am going to be running 37" tires on a model 20 axle with nothing but a One piece axle conversion (open of course) also to note, the axle Diameter is the same, D44 is a 30 spline while the Model 20 is 29 spline, and the ring gear in teh 20 is larger.
KEEP THE 20