Oh Man I hate those, no matter what you do you'll be wrong, Edentulous People tend to go protrusive as they relax, if you try to take them back there's a 50/50 chance they won't tolerate the change. A lot of times they're using too much adhesive or wearing there dentures all night and have swollen inflamed tissues from chronic candidia infections so getting a good impression is nearly impossible too.
From what I've seen, I go for the centric bite with 10 degree teeth, if they revert to the protrusive bite, the dentures can usually be functional with only some occlusal adjustments. The chances of a remake will be higher than normal.