If you are REALLY trying to save pennies you can get industrious and build yourself a base plate and adapter ring to put under the hood and support your bubble. I wouldn't scrimp on the bubble as it's highly visable and subtle things show. Same goes for the bubble grills. The best bubble on the market is AAR fiberglasses version, or Gene Gregories, both cost about the same $300-$350.00. The grills add $250.00. Gerome Verbit makes the best grills period. Art Pacheco at Six Pack Performance in New Mexico sells Genes stuff and Geromes grills. On the super cheap you can buy plastic bubble grills on ebay for under $100.00, they work but you will notice a fit difference between them and originals.
If you want the best reproduction base plate and adapter ring those are also sold by Art Pachecho (Gene Gregories parts). Gene went further towards "correct" with the subtle details on his base plates and adapter rings like OEM appearing welds (as compared to the other source who's are incorrectly spot welded) but Art/Gene is slightly more expensive too, bottom line? Either vendors will work but you get what you pay for. Plan on an adapter ring and base costing you around $1,200.00.
The internal hot & cold air doors and cables, etc. add to cost and are not really needed, plus you can always add them later as budget allows.
Your last choice is a fiberglass base and ring (Year One) but they don't fit really well and are still a few hundred bucks, wasted money IMO.
Good luck and happy hunting!