Hey Brodie
I ended up scraping the mx5 idea and went with original seats.
I found a set of front and rear sears, blue with grey velour. I taped up all the velour then sprayed the blue vinyl with black vinyl spray - duplicolour matt black. The end result was great.
The mx5 seats would fit with some major modification to the seat rails, but they didn't quite sit properly and they were a little high, so your head hit the roof.
I would look at getting good stock replacement ones - mine cost $150 for front and rear. You can also purchase vinyl cover kits for $300ish