rkc....i will semi agree with you about wild discus being ugly. they arent supposed to be uber pretty. they have to survive. i like they way mine look very much, as oppose to the pigeon bloods and turqouise discus i have. they have just different patterns and marks on them, plus the way they behave is waaay different then the domestics. the two wilds i have raine over the tank, none of the other fishes even come close to messing with the wilds. however the wilds will put the dom. right in their place.
An F0 or F1 would be a good place to start for a string blood line. they are still close enough to the parents to take after their behavior. they will generally have the same color and act similar. the best thing to do is if your gonna start breeding, once you get into the F4 or so batches add soem wild fishes into the breeders for your "f5" generation. the wild wiill help add genetic differances and strength to the blood lines. i know many discus breeders will add a wild into their regualr breeders now and then to kinda "clean" the line up