First and foremost, You should know what you want and it sounds to me like your not sure, so PHS doesn't matter. When I bought my first GTO, I had a pretty good idea what I wanted in the car. IMO for the puriest, a numbers matching car PHS is a must.
For the person who just wants a muscle car that looks and runs good, PHS is not that important.
The most important thing is that the car is sound mechanically and you can enjoy it. Too many people jump into this hobby with no idea and end up spending a bundle or get frustrated and suffer a loss, so take your time to thoroughly checkout any possible purchase.