Man, you need to take off your mullet blindfold.
The stock suspension on a 944 Turbo S would run circles around some of the best shit you could put on old POS notchback.
For that reason all the 944 would need is a new set of shocks and struts which will cost much less than an entire new suspension for the rustang. Maybe a new set of bushings if its getting a little too old.
For that reason you save the money you would spend on buying a whole new suspension for the ferd.
Bump the boost, change the chip and put some big rubber on it and you have a great car for both on and off the course that will be worth something instead of some shitty old frankenstang that will never be that good of an auto-x car and be a black hole for all the money you put into it.
For the $7-8K the 944 turbo will set you back what will you ever be able to achieve with an old turbo 2.3 notchback anyways?
And why bump to SM2. If you keep your mods mellow enough you won't bump, yet have the performance of a turbo miata.
If I lose the 930 a 944 Turbo is one of the options I'm concidering as a replacement.