I'd suspect, seeing as you have a fair amount of experience, you might be quite attractive to some operators. Most people starting out on floats seem to have <300 hours, with ~ 50 float time. You'll need a float rating first off - there's a couple of places on the West Coast that are open year-round. The time for looking is probably mid February to mid March. Red Lake, Ontario has several operators, Yellowknife also. You'll probably have to be in Canada first, though.
In terms of fire suppression, you'll need some decent multi-time (if you don't already have some) for all of the operators. If you were cunning, you might think of trying the Maldives - two operators there that operate Twin Otters on floats - neatly killing two birds with one stone.
Conair in Abbotsford, BC has the BC contract, and some of Alberta. Airspray, in Red Deer(?) Alberta has the rest of Alberta. Saskatchewan, Manitoba, Ontario and Quebec are all government-run for fire supression.
Good Luck.