If I were to build a recovery Rig I would start with something bigger then a SWB Jeep. A J20 or M715 would be a better starting point. There is simply not enough room in a CJ for what would be needed in a dedicated Recovery Vehicle.
Winches: one front one rear.
1. Rear 12000 lb minimum, would be PTO or hydraulic with a dedicated hydraulic pump. No electric can compete with a Hydraulic or PTO for continuous duty. Suppose someone blows an engine, transmission or Tcase at the bottom of a half mile of very rough very steep trail, such that the rig may not be simply pulled out. This could lead to pull after pull with a winch to remove the damaged Jeep. This would burnup all but the most over sized electrics.
2. Front would be Electric with power out. Rated atleast 2 times loaded GVW. Shivs and rub blocks provided such that the front winch cable can be run to the rear over the top of the rig. This winch would be used for self recovery and delicate operations like righting a flipped Jeep. Dual Batterys and heavy alternator would be provided. This would also be used as part of Idea 4.
3. At least one quality cum-along with of 5 ton or greater rating. This would be used for very fine adjustments in bending parts and in moving damaged Jeeps short distances when rigging a snatch block is not useful time wise.
4. Appropriately sized box tubing to form an A-frame attached to the rear bumper. A spender that could be staked into the ground could be provided to use away from the recovery Vehicle. The front electric winch could be run over the top of the cab to raise and lower the A-frame, while the rear winch line runs over a block on the A-frame to get better deflection and or lift stuck rigs. This would be very helpful in the mud. Many times by the time someone calls you they are in the mud up to the frame. Trying to pull a rig out of this situation is nearly impossible. However, if it can be lifted and set branches, blocks, rocks or grates it is often easy to pull out.
5. Rope, chain, cable, Blocks and Tackle. The exact list will depend on location type of wheeling and personal preference.
6. Land anchors. Often a tail holt is needed and none is available. Anything that can be driven or pulled into the ground can be most useful. Metal Grate and concrete forming pins work ok in relatively solid soil and tundra. The grate can also be used under wheels in mud or sand.
Power: OBA, OBW, OBP
1. OBA, on board air, Here it is just about imposable to beat the York with 2 to 5 gallons of reserve tank. It works, It's cheap, and it is proven.
2. OBW, on Board welder, this should be of the SMAW (stick welding) or FCAW (flux core arc weld) types, all others should say home. MIG and TIG rely on shielding gas that is a pain to transport and is easily blown way by the slightest breeze. With these processes a lot depends on the chose of electrode or Wire. These should be chosen without regard for deposition rates or cleanness of weld. The only thing that matters are Penetration and ability to deal with contamination. In SMAW electrodes E6010 or E6011 are good depending on DC or AC, In FCAW an E71T-11 or similar is good. These burn very different then E7018 or MIG so practice is a must, they also produce lots of splater. However, they will weld grease and paint covered steel in the middle of a hurricane.
There are several products that clam to turn an alternator into a SMAW or FCAW welder, in addition many have come up with there own methods of removing regulation to the alternator to make welding currents. However, I have yet to see a picture of a weld made by one of these that was any good. Perhaps there are some but I have not seen any. The pictures a have seen have looked like Bird $hit. Weather this is due to operator incompetence or inadequate welding power, I do not know.
On a dedicated Repair Jeep I would either use an purpose built Welder/Generator driven by the engine or driven by a separate engine. As I have said I have not seen a good bead made by a alternator converted to a welder. I still plan to build a welder alternator on the jeep to see what it can do but from what I have seen I expect pore welds.
3. OBP, On board Power, again there are products that calm to turn the alternator in to a 120 Volt DC generator. Perhaps they work but given that these are the same company's that clam their weldernators do such a good job I have my doubts. However, this combines nicely with many engine powered welders that include a generator ability.
1. Complete tool set including common hub sockets, Pullers, spreaders and the like is needed. Naming all posible Items is a post or 2 in and of itself and the final selection will depend on experiance and Vehicles commonly needing repair.
2. Since we have Air and Power, We should have Air impact wrench, Air ratchet, Air chuck for filling tires, Tire patch kit, Common Tire tubes, Grinder Air or electric, Drill air or electric, Lights, extra.
3. As part of Idea 4 under winching a solid rear bumper with receiver hitches.
4. A vise/anvil mounted on a receiver hitch. I can not imagine life with out a vise and anvil.
Parts: This will depend on the Vehicles commonly needing help/ parts, and whether this is a for profit, deal or a help your buddy's kind of deal as some of these involve large investment.
1. Good selection of conversion U-joints
2. Drive shafts with long splines that maybe cut for use in many lengths.
3. Common Steering boxes
4. Common TRE's
5. Common front inneraxles with long splines that may be cut to any length
6. Common front outer axles that maybe joined to common inners on an as needed basis.
7. Common Rear axles with long splines to be cut to length.
8. And so on and so on.
In the end it depends so much on what you plan to do with said Rig and what your abilities are that the sky is the limit. How about a fully equipped machine shop to be slung in with an CH-54 Skycrane.