i did my exterior first, i take some s**t for it being slow and looking nice but at the end of the day i turn heads and hear nothin but "hey that's a nice car man" anywhere i go...and i've done some minor performance mods along the way, like i/h/e
next comes my engine...
IMO also, it depends on your money, appearance is like 100 here 200 there sometimes 500 here, and paint is expensive but other than that it's more affordable to me...engine you are better off moving to a b series altogether and that's not cheap plus if you turbo it that's not cheap either plus tons of other here and there things...
just my 0.02