Swapping engine of Khyber is not a good Idea. As the body of Khyber is weak, no matter what the condition of the car is. Japanese Swift or Club Cultus is a better option. U may Swap any of these G13B or G13BA. Its better not to go for the 16oocc engine. G13b is EFI, 16 valve, DOHC and 100HP. G13BA i guess is good carbrtd version. It is 8 valve and produce 67HP (Good fuel economy too). Moreover the thrust and more HP of G13b will produce more wear and tear in the Suzuki Khyber car (As its perhaps the most Fragile vehicle on the road).
Starlet and Kia Pride are better in terms of Body strength to sustain excessive load. Do use 4 wheel disc breaks. Otherwise we may loose u dear :-D.