I remember watching PTI and they had a reporter who use to vote on the Hall of Fame, but said in the interview that he and the others who were voting at the time of Warren Moon getting into the HOF, to ignore what he did in the CFL. So anything in that league doesn't count towards consideration into Canton.
Otherwise you would see someone like Damon Allen, brother of Marcus get voted in as Professional Footballs all time yards passing leader. I think Flutie would have a chance based on his time at Boston College with his little mark in the NFL.
As for the certain crop, other than the pre-mentioned Brady, Peyton and Farve I don't really seeing anyone else get in, of course like others I believe Palmer and McNabb could be on the right track but the NFL is a what have you done for me lately league these days and the QB carousel that so many teams go through make it harder for anyone to have the longevity that they could have had in the past to make their mark towards a HOF career. Here today, gone tomorrow as they say.