Well, whatever you do don't have ANY emblems on it when you get done! The GPers here are unanimously opposed to cars with writing on them of any kind, its like emblems take away horsepower. Personally, If I built that I might just put Sprint6 emblems on it. To quote a member here: "Taste is relative, but acceptance can be a factor."
As far as the build itself, I like the idea. Just remember thats a Buick engine, nothing Pontiac about it so its not likely to set well with purists of course. When I mention my 3800 at a Pontiac forum, it becomes a ghost town. Just like here if I mention the 455. Luckily, the only person who has to like the car is you.
The proposed setup would be giant fun if you ask me, though. Do it. I don't think theres will be a great deal of hurdles to jump to make it happen. Accessory drive would be one challenge, but since the 3800 AKA Buick 231 has been around since '64 there has to be a combo that will help you swap. Would you use steering pump and alternator from a 3800 car, or aftermarket, or 67 Firebird?