I'm 2 inches shorter than you, but the dimensions fit otherwise. Wearing booties (not shoes with soles), I find the Explorer to be just a little looser fitting than my Valley Nordkapp. I have about 4" to the bulkhead in a stock Explorer, and 7" in the Nordkapp. I prefer padding out a bulkhead over foot braces in any boat.
You are not as big as many others I know paddling Explorers. If you feel that your legs are too low under the deck, I suspect that stretching to improve your flexibility might be a big part of the solution. Maybe I am off base here, but it is something to consider.