(2) This is the most important question: What do you want to use this '92 PreTaco (Toyota Pickup) for?
(3) If it is - or is to be - a daily driver / beater / utility truck ... My advice is to fix it. If you threw the timing chain there may be more damage than just the water pump (housing?). If it were me, the truck was worth saving, and I could afford it, I'd simply swap in a rebuilt / remanufactured 22R and call it a day.
(4) If it is - or is to be - a dedicated show truck or race truck ... This is the only case where a major transplant (2RZ; 3RZ; 2JZ) might be justified. Any of these transplants would require major mechanical / electrical surgery and cost as much or more that a 1992 PreTaco is generally worth.