You could probably substitute any kind of nut flour as a binder. I would find coconut a bit sweet.
I guess it depends on whether you find the eating of the matzah itself important (the eating of the unleavened grain) or just the avoidance of the leavened grain. Some find the matzah part of the point (but then I would just eat a small bit of matzah ceremonially and move on with it, not grind it up in gefilte and other recipes)
MTA: because it is rare I dont have more to say
"When I got too tired to run anymore I just pretended I wasnt tired and kept running anyway" - my daughter Age 7