86 GT's came available with the white paint and grey Aero Ground Effects. it would just need the interior, badges, and stickers.
I've thought about putting a Fastback clip on an Indy. but honestly, I wouldn't do it an Indy is what it is because of what it is in it's stock/unmodified form.
good idea - sure.
a local fiero buddy of mine has an 88 3.4L TDC Getrag Fastback GT with side scoops added along with all the INDY fiero badges and the whole interior. I liked it. but if it was white I think I'd like it more.