We are wanting to build a true 4 seat amphibious airplane. Live load 1200 lbs, 300 Hp range, 150+ cruise speed, composite construction. I have built almost any project imaginable, construction processes, wiring, etc. although I will have questions feel totally comfortable with. The problem is design and engineering. I can not find plans I'm interested in, the seawind is similar but way to heavy and hp needing. I want something along the lone of an Icon 5 but four seat and higher hp and speed. I appreciate any ideas or help.