Let's look this in another way. It might be good to crunch the numbers on the weight of a SS7 on amphibious floats. If you build the SS7 light you can get an EW around 750# on wheels. On amphib floats you could probably get an EW around 900# (remove at least 50# of landing gear and install about 200# floats). This gives you over 500 lbs of useful load @ 1430 GW.

Maybe you can have your cake and eat it too.