I would say Reed and here is why:
Do not underestimate that when looking ar Reed's numbers, the Bills won a ton of games...and when you are leading in a lot of games you tend to pass less....I can recall a few games where Jimo would be 9-12 for 130 yards or so in a 38-0 blowout (not 100 percent accurate here, but I hope you get my drift)....
And I agree about the consistency...Reed has Moulds beat there...Moulds would have been REAL good with Kelly, but I do not believe his numbers would have been any better then Reed's because the Bills had more leads in Kelly's era.