... I have 33s on it -- what gears would suit it best?
and they are re-geared through the transfer case correct not at the diffs?
You can change both transfer case gears and R&P, although on a 4WD vehicle you must make both front & rear differentials' R&P ratios the same. T-case gears are identified by their low-range reduction (e.g 4.16, 4.9, 5.13, 6.1, 6.5 etc.), although it's often the high-range reduction that really matters on the highway.
Changing T-case gears does not affect speedometer (in-)accuracy, althought tire diameter and R&P ratios do. For best speedo accuracy, change tire size and R&P ratios together. This also minimizes the additional torque stress on the T-case and its mounts. True 33's are about 26% oversize, so ideally you would choose a R&P ratio that's about the same, i.e. 3.73 x 1.26 = 4.68.
The closest avaiable Suzuki R&P ratio is about 4.6 which would be a good match for true 33's. If you have a pre-'88.5 Zuk 5-speed with the 0.795 5th OD gear, you could even go up to the 5.13 R&P.
Alternatively, you could mate a 4.16:1 T-case gearset with the ~4.6 R&P and be about right (in high-range) as well, and have pretty good low-range, the equivalent of 5.22 low-range gears all by themselves.
If you put ALL the reduction into the T-case, you'll have to really reinforce the T-case arms and mounts, since it carries all the reaction torque. There's a good article from Brent from Trailtough at:
http://www.trailtough.com/index.php?view=article&catid=36:techinfo&id=60 There's a good chart at:
http://www.lowrangeoffroad.com/index.php/suzuki/samurai/transfer-case.html , but above 31's or so, you should really consider changing the R&P ratios in addition, if you don't want to risk breaking driveline components. Driving style will also have a large influence on your results.