Normally if you would go to the main Kabarias they would tell you if an engine is Kabuli or if its locally used and there is a price difference between the two. If you don't trust the kabaria enough to distinguish between locally used / ganuine kabuli stuff, you definately should not be buying stuff off of them.
Once you are confident that its a genuine Kabuli engine, you can quite safely take a bet that its something that is done 40-60k and is in reasonably decent shape (around 80%). In some cases the kabarias would also guarantee that if there is any blow etc they would replace or return the engine. Its important to get such a guarantee for the newer petrol engines where the various external components that you get (AFM, computers etc) may or may not match up and need to be replaced....
All said and done, a complete overhaul done by an expert mechanic is unmatchable in terms of long term satisfaction and getting the best out of what you have. At times the performance may even feel better than stock once you run in the engine completely which may be as late as 10k+ kms (Akif Janjua estimate). The reason for this could be the use of slightly bigger pistons etc. or may just be my perception. Going to a good/great mechanic cannot be overemphasized here!
The 22R is a decent enough engine for your needs with 108 HP and 138 ft.lbs (though there might be some variation between the models). I assume that rebuilding it completely and properly could cost you around 50-60k (again there is variation between genuine and chinese parts) and may be less if some parts (pistons etc are reused). Ideally you should also look into changing the carb (which is available ~15k) to get the best results....
All th best!