Depends on what you want.

I'm no expert like some of the turbo guys, but you will get the most horsepower out of an 88-89 set-up - up over 200. That's what I'm using.

There will be a substancial power gain using any of the StarQuest set-ups.

And you're doing right buying a donor car. I did mine piece-meal and it has taken way the hell too long. There is a definite advantage to being able to take apart before you put back together.

87 Montero, bought new, by me -
88/89 intercooled Starion Turbo engine-
with awesome audio.