Looking for 15 gauge "DA" style finishing nails in the Kawartha Lakes Area
(1 1/2" - 2 1/2") for Porter Cable DA250B finish nailer. Home Depot, Rona,
and other Lumber Yards in my area only stock Bostitch "FN" style. Any help
would be very appreciated

Look in the yellow pages under "Fasteners Industrial", "Nailing Machinery",
or "Tools Pneumatic".