Why dont you visit bilal gunj?
How can anyone give you the estimate, unless he is not a shopkeeper.
My estimate is as follows:
B16A, 160HP, fuel hungry, not suitable for CNG, short stroke engine of Civic, not compatible with Accord, needs modification including engine mounts, 100K Rs with gear box, if available.
B16B, 185HP, short stroke engine of Civic type R, not suitable for CNG at all, not at all compatible with Accord, needs heavy modification including engine mounts, 175K Rs with gear box if available.
A18A, 110HP your best bet, would be around 30K Rs.
A20A1, 98HP A20A2 102HP CARB, A20A3 110HP and A20A4 120HP both Fuel injection, more powerful, fuel economy is less then A18A, can cost you around 40-45K Rs.
B20A, first generation will fit in, second gen is for prelude, very rare, no idea.
H22A, needs some heavy mods, engine mounts, gear box, wiring, radiator and possibly brakes too, not very good fuel consumption for city driving in traffic jams, around 75K Rs.
I will still insist a visit to Honda 3S, and check the possibility of overhaul.