Sell your leafer and get a coiler......cheaper to mod as well.....stock springs, 2" poly spacer, 1.5" body lift, no SYE and running 35s.
Biggest thing to consider, wheel/tires - size and wheel offset. Go from there. If you go too big in wheel/tire size, you'll need different axles to handle the weight and wheeling the size of the tires. Keep wheel/tire size acceptable, then you may only need to swap out your axle. (I haven't read if you are planning to do something with the stock D35 rear axle.) Get estimates for r&p and lunchbox lockers install, and possible unit bearings, ball joints and u-joints.
The SOA gives you better approach angles due to the location of the front shackle relative to the axle. Introduces lots of other problems using stock axles, ie steering, weld-on perches. Has higher il-effects than lift springs SUA in off-camber situations. Swap in 78/79 Ford F250 front axle for SOA and it gives you better options, ie bigger brakes, SOA already (5/8" off center of YJ springs (absorbed in bushings or add in offset shackles)), high steer capability, bigger r&p, still high pinion, same 297 u-joint but bigger shafts, shock mount relocation, much much heavier axle. Swap rear axle from same truck to the rear (usually D60), requires welding spring perches and shock mounts and redoing rear ds. Regear to match your tire size. Wheels will need to be 8on6.5. Gear them to work with your tires. SUA introduces greater potential for axle wrap. SOA usually requires a SYE for the stock tcase.
SUA is a more appropriate for the milder wheeler. Less problematic in comparison to SUA. Same situation with your axles. Need to figure out what will work with your choice of tires/wheels. The stock D35 rear axle can be mod'd to handle 35's moderately. Swapping in another axle (8.8, 8.25) is viable option. The front D30 axle should be able to handle 35's easily. There are upgrade areas for it as well. SUA is more of a bolt in situation. Add a slight body lift and motor mount lift to drop the rear output of your tcase. It is similar to adding drop brackets to your crossmember. Lift the front or drop the rear of the driveline. Or add SYE ($200 or so for tcase and $200-300 for rear ds) and need not worry too much.
Comparing the upgrade costs to axle swap cost is difficult. Many do their own work and there are slight differences in hardware you choose to use with them. Labor costs are variable in different locations across the US. Making your stock axles stronger can be costly in parts, but they will last. Swap in heavier axles (right choice of axles), then rebuild and install will also last.
For your $2k budget, I'd go 33's, 4.56 in axles, lunchbox lockers, swap in either 8.8 (Explorer 95-01) or late model XJ (8.25, upgrade to 29spline shafts) or strengthen D35 (Super35), SUA with 3.5-4" lift springs (look for Baja bushings), longer shackles, rebuild axles to handle (bearings, ball joints, ujoints, etc), SYE, front/rear bumpers with recovery points, winch (8000#). Then in time, add 1.25" body lift, TJ flares, flat belly and go to 35's. Once you get more and more experience, better job, more income, etc., then look into going bigger tires, swapping in Hemi driveline, bigger axles, toter, trailer, etc...
