well time and time again, AAR always gets the nod as being the best for fiberglass parts. What engine is in the car, a B or RB? If you have a B I think a holley street dominator should let you use any regular sized carb and air cleaner under the stock hood and its a really good intake. may be fine with an RB too but I dont know for sure
http://www.up22.com/ I know, I know !` But they make a bolt on 6pac scoop. This company's quality is not the best for bigger panels, but I have had very good luck with getting my scoops there ! This may be all you need without trying to bond a fiberglass scoop to a steel hood. It shows the bolt on flange is on the inside of the scoop so the bolts don't show. Even if you would have to fix the fiberglass it would only be the scoop ! Something like that you could just cut your hood and bolt on and go !
If you want a full glass hood AAR is the ticket ! big $ vs low $