Complete Overhaul, get it done from a reliable source. An overhauled engine is as good as new, swapped are old engines and their life can never be determined properly.
Take it to toyota and ask them for an estimate, then take it to your mechanic and ask him for an estimate for a complete overhaul. If the difference isn't much, then toyota as it would be guaranteed, if there is a significant difference, then a decent local mechanic. I know of one in Pindi if you are interested