Sir you can get the 1SZ FE if you like the A/T or the 2NZ FE from old XLI with a manual tranny, both are bolt on swaps and both will reduce your car's value by same margin since you will replace the original engine.
I recommend a overhaul of the engine, if its possible.
You should go to a Kabaar market like Shershah in Karachi, or Bilal Gunj or Peshawar, whichever is more convienient to you.
You can get the work done for 50-60K Rs depending on the engine swap and in addition what you will get for your original engine.
Regards