A good friend of mine owns both a 4runner with a 22r, 5 speed with a Marlin Ultimate and a Truggy 4.3 and an auto trans (I believe its a TH 400) and a Marlin Ultimate backing it up. Both do very well and they both have plus' and minus'. If you go with the auto you should get a custom torque converter with as low of a stall as possible so that it won't feel like you're in neutral going downhill but the downside of this is when it's sitting still it won't want to stay put. You almost don't need crawler gears since not only can you create your own reduction with the proper use of the skinny pedal but you can use your left foot to slow your progress with the brakes. The auto is also easier on parts since it will absorb a lot of the pressure put on other parts, the stick is unforgiving in this area. The stick with crawler gears is awsome though, I love a stick with gearing. Just drop it in double low and watch it climb walls. It really boils down to what you personally like, I like the autos they make it cheaper to build a crawler since you don't really need the crawlbox saving you some $ to put somewhere else on your rig.
