the main thing that I found with the NEXTAR and float installation is the proper gear set up.
the floats I am using are Goldberg Superfloats and they have a preset gear locations(not like they couldn't be moved with a little work) but I chose to use the locations provided.
there is some holes that need to be covered over IMO like the auto pilot sensor and the stock gear holes with some covering to have a better water seal,you then can open them up when you want to fly off land.
as well as pulling the nose gear.
the fuse is also curved so if you wan to do a temp. mount then you will have to fabricate something to fit the curve of the bottom of the fuse.
my plane was pretty much sitting collecting dust, so I cut open the fuse and made a solid mount from plywood and used nylon bolts to attach the new front gear too.
if I decide that I want to fly off land again with it I will put on a tail wheel and make it a tail dragger but this plane will be a full time float flyer for now.
another thing to consider is the power plant the OS 46fxi will get it airborne I would think but your not going to have much performancewith all that weight hanging under that plane.
I also went with a more powerfull OS 61fx I had handy.
so far I have the floats built and covered after this post I am heading to the shop to work on planes so I will probably stary re-covering the fusealage that I stripped,the covering was in bad shape and I had crashed it a couple of times so I wanted to do a dammage check and reglue any broken parts.
so yes itd do able