Here's a link to the Type Certificate for the 185:
https://rgl.faa.gov/Regulatory_and_Guid ... Rev_40.pdfIt's listed under Textron, not Cessna, since Textron now owns the Cessna line.
Anyway, you can compare models there. The older and slightly lighter planes were equipped with the IO 470, and I think you'll definitely want the 520, so I'd lean toward the 185 E or maybe the F, which was the last of the line. The very early E's had a slightly lower gross weight than the later E's and all F's. On floats, that really starts to matter.
I've heard of early 185s being retrofitted with an IO-520, but I can't recall what that requires, or if the gross weight also increases with that engine.
In any case, even the later 185s can be lightened up a fair amount, and if it were me, I'd look for a late E or an F, then work on lightening it up some.
If, as you say, 99 percent of your mission is you and "stuff" one of those planes should work fine.
My preference on floats would be EDO 3430 or Aerocets, but the Aerocets are going to be precious. The CAP 3000s are going to limit your gross weight a little, but they perform well enough, if you keep it fairly light. The only floats I'd really steer away from are the early PeeKay 3500 A and B models. They are doggy and heavy. Which is why PeeKay developed the 3500 C and D floats.
Good luck with your research. The TC should help some, then you'll have to decide if what you find for sale will meet your chosen parameters.
Don't get me started on Beavers.....I literally cried when they took my Beaver away and replaced it with a very nice 206.....but that's a different story.
MTV