Any .12 , .15 or .18 will have the same mounting requirements so you can use whichever you decide to use . Neither of those bodies will fit and you should use a body that is made for that truck . As for side or rear exhaust , sure your stock pipe and header are for side exhaust . Your truck is set up to use rotary style carbs , but sure you can get a different servo horn and make it work for a slide carb . You need a threaded crank engine for your truck with a rotary carb with side exhaust . But you can get a different header/pipe and different servo horn to go with a rear exhaust slide carb engine if you want to .

"will any proline2.2 tire fit on any proline2.2 rim" yes

Losi Truck rims or Proline rims for XXX-t or NT will fit on the rear and the front .