What I would do.
Quick and dirty;
* Start FS, in a plane, at a ramp
* Slew to altitude
* Rechange out plane for float plane
Ingenious route;
* Open float plane 'aircraft' config file with Notepad
* Copy/paste in landing gear (wheels 'type' sections, 4 strings) into the contacts points section
* Set up wheeled (invisible) landing gear height in FS, save settings
* Boot up where ever you want in Float Plane
Note 1; I believe you will need to set landing gear to rise lower (seconds time sections on Contact points per string/gear) so that when you land, gear is up, and floats will not flip you over
Note 2; You can easily copy/paste the landing gear (wheels version / type) from another existing plane (Caravan float plane) and paste it into the said new float plane and adjust widths and such (X,Y,Z coordinates from 'floats' contact points) so they match / align.
What 'version two' does is enable you to land on the ground, and boot up on the ground. I did this with the FSX Beaver, works brilliant. You need to dial in the height though, so that will take some 'reset/reboot/reset/reboot' until you are dead on. Drive around in the dirt to note your positions points.
Bill of the gray eyebrow people...