I bought a 79 Buick Regal Turbo new and it was called a "Sport Coupe" just so you know when looking for parts. I don't know if the header panel would fit or not, I would contact GBodyParts.com Online and ask Brian to help you out.
By the way Hot Rod magazine did a write up on the 79 turbo and did a bunch of bolt on's. And I did everyone that they did, I surprised lot's of my peers with there V-8's before anyone had any idea what Buick was up to. Some of the bolt on's that I remember where dual exhaust from the cat back, mack air cleaner, bigger jets for the rochester 4 barrel, rework the butterfly in the four barrel to open up more, water injection, boost controller under the dash, boost/vac gage, shift kit... that's all that I can remember.
If anyone can find that article u should post it in the b4black section. Wouldn't mind checkin it out myself. I love those carbed turbo cars and I'd like to see one with champion heads, cam, the whole nine just to see what they can really do Oh yeah, the header panel is probably a no go. I think u could do like a 80-82 header panel with the 4 headlights though. I'll find some info for ya.