If you can get a 99 that was originally fitted with the H engine then it will fit just fine apart from a couple of bits with the gearbox. However, fitting the intercooler, and the various extras involved with overgrown EFI may cause some headaches
You need the 99 front plate as the 900 one is totally different.
You need the 99 inner drivers as the rear handbrake 900's used a different size spider.
You probably need to swap the gearshift stick etc. if the car is a manual.