There's a 10 foot jon boat on craigslist in my area for $100, would that be too unstable for someone my size? I'm 6'4" and 275. I wouldn't be trying to trick it out, just put a trolling motor on it and maybe a clamp on seat.

You should be fine if your sitting 90% of the time if it is a narrow design. If its say 48" wide on bottom and got at least say 54" beam, you should also be able to walk around a bit. All depends on size buddy.

Cool, thanks.  I'm not sure on the width of the boat.

I would not recommend a 10' john for anyone your size. It would not be safe and especially so in anything but dead calm water.

Save your money and get a bigger boat.

Most of the painted/riveted jon boats in the 10' length have a 32" bottom and a beam of about 46". The capacity of those is about 320# max for person and gear or 275#-280# in persons.

If it is one of the old unpainted, kind of rough aluminum foil looking ones, they have a 30" bottom and would probably sink when you stepped in it at any place other than dead center.

I am about the same size as you and I had a 10 ft jonboat that I used just once. It was way to unstable. I got a 12 ft one and it has been just fine.

Thanks for all the input, I'm gonna hold off and try to pick up a 12 footer or something.  I can't have a boat trailer where I live so I'm pretty much limited to a canoe, jon boat, or something like a bass raider.