If you have structurally sound doors and they are only wavy and have bondo on them, there is NO WAY IN HELL I would change to Chinese repros!
If you think that the Chinese repros won't be wavy and need filler you are mistaken, if you want them nice that is. They will NOT fit as good as yours, the window regulator and latch won't bolt in as nice as yours, there is NOTHING that works on that Mustang like the original parts, stick with them.
You would be surprised to find that many times "waves" in bodies and "lots of bondo" is there because of poor repairs were done on it.
Let's get this straight, (pardon the pun) the waves and lots of bondo are a result of poor repairs NOT doors in poor condition.
There is a VERY, VERY good chance now that you striped the paint and fillers off those doors they are much straighter than they were before you stripped them!
They will then need a little filler here or there or maybe a thin skim coat over the entire door, but either way they are STILL way better than Chinese repro doors!