Searching for a small aircraft that is not currently on floats with the intention of putting it on floats, you also need to figure out how commonly that make and model was installed on floats....ie: How many floats are out there with appropriate rigging. I have never seen an Aeronca Chief on floats, though they are approved on floats. Lots of T-Crafts were put on floats, lots of Champs, etc.
Again, if you start thinking too big initially, you may spend all the $$ you can scrounge on just the airplane and be no better off as far as SES goes, cause you can't afford floats.
First you need to decide how much money you can put together, from savings and/or a loan. THAT will drive your airplane choice more than anything.
The 7AC Champs have increased in value a LITTLE, since they're now LSA qualified. Same with J-3. But, there are lots of little Champs out there that aren't LSA eligible, whose prices are still reasonable. Like the 7GC, FC, etc.
Do some poking around. They're out there. But, first go to the credit union or bank and find out what they'll work with you on. Then call the insurance companies. If you're getting into a seaplane, call an insurance broker who does SES insurance as a specialty. They'll know which underwriter to go to.
Good luck


