I just checked out the Wilderness Air website. They say 250 hours minimum, and they will provide 50 hours training in the right seat. Better than 300, but it still leaves me some 23 hours short... If I had the time and cash to spare, I'd definitely go do the 50-hour bush course in Kelowna, BC.
Given flyboy's last comment, I might just roll the dice and hope that what I lack in hours can be replaced by my M-IFR rating and my killer attitude!