New to the forum and to A-bodies - advice on a build direction

My first question is, how deep are your pockets? This is hobby ain't cheap, no matter the direction, but the pro touring crap (my opinion, because it's tacky as hell and been WAY overdone) can get VERY expensive. So keep that in mind.
Really depends on what the market will take. I could go either way on this build. I agree that some pro-touring builds can go way beyond what I personally prefer, but I guess it's all subjective. But I tend to focus on the objective things related to driveability and safety. The best thing about these old cars in general, IMO, is their looks and vibe, but I think it'd be hard to argue that they perform and drive better than nearly any modern vehicle. So I try and focus on those aspects, and then address some livibility, because ultimately if someone isn't vibing with the interior it's just going to sit and go to waste. But it's a fine balance to keep their character and improve them. Too much improvement might neutralize the nostalgic feel some customers long for.