We overhauled our 1.3L Corolla in Marikina before and it cost us around 15K to change the timing belt/tensioner bearings, gaskets, piston rings, plus some suspension parts. All parts were OEM (bought it at MR2 in Banawe) and also included labor and machine shop costs. Whats important is that you have agood mechanic and you shop around for the needed parts.

If you get a surplus engine, its recommended that you recondition it as well (change timing belts, gaskets, etc) and the cost will just go up higher. Since your stock engine is a carb, you;'ll also have to do wiring work for the ECU and change your fuel pump as well.