Then I saw disc brakes in back. Hmmm. This car is 1989, not 1979! I don't know Mazdas...
You might check out the guys over at Hinson Motorsports
Looks like they have a kit for a vee-thing swap.
If you are looking to stay inline how about a Swedish solution like a Volvo T5 with a Getrag M90? Pre-99 has no VVT so the electronics should be lighter.