FYI, I went to the local kabaariyaas today, gathered some info regarding city engines, sharing here as it might be helpful in some way...
In 1.5L, there are two versions: i-DSi and VTEC as you already know. Kabaar walas know them as "8 kaayl(coil) wala" and "4 kaayl wala" respectively.
i-DSi swap will set you back around 25k Rs including fitting and by selling your own engine to the guy, wiring etc will all be the same, just bolt to bolt assembly swap.
VTEC will cost you around 40k as it needs its own ECU and all the necessary wiring.
Both are possible and the swap in either case is a game of merely 8-10 hours or so....
The guy I went to was offering 3 months FULL warranty of the motor, even if the compression results are bad or you find out its repaired, the guy is bound to take it back...