The 99+ Vitara are larger & heavier and with the 2.0 more powerful.
The engine uses a timing chain rather than a belt and if oil changes have not been done on schedule the chain tensioners can give trouble - start it from cold and listen for timing chain rattle, if it does walk away, the front differential has an air operated free wheeling disconnect clutch that can also be problematic, and a small number of vehicles have had inadequate corrosion protection causing the front cross member to rot prematurely.
I'm not certain on the rims - I drive a '98 2.0 Grand Vitara, which is essentially a four door of what the US calls a '99 Vitara and 16" rims are standard - 15's will not clear the front calipers.