Get as large (wide and long) of a square bowed, light gauge aluminum boat as you can drag over stuff; maybe a 14 footer.
Too narrow and short of a boat will draft more water. By the time you, your son, and gear are in the boat it will be loaded more than you originally imagined.
Both of you, wear your PFD.

Another thing to consider is location. While I can barefoot beaver trap down here most winters you are in a different situation entirely. Getting wet here means being uncomfortable until I can get to the truck. Wet up there might mean hyperthermia before you can get to the truck. Plan accordingly and prepare for worst case, better to have a plan and not need than no plan at all.

I trapped out of a 13’ Old Town Discovery. Being short and 40” wide it was quite stable. It could be paddled from the back or it could be oared from mid ship oar locks. I had a side mount transom that I ran a 3 horse motor from when needed. I managed to load a Moose out of the Superior National Forest with it far exceeding its recommended capacity. It wasn’t any less stable then a 12’ Jon boat ! Many times I threw it on my shoulders and carried it 300 yards to launch. Try that with a boat !

https://www.sportsmans.com/boats-ka...msclkid=2912396664be16c38ebd5ce8a2b9d668

Did you buy it???

Another vote for a Grumman sport boat. I run a 6.5hp Go-Devil on mine - (Go-Devil is the crawfish model, shorter long tail). However if your checking traps you may prefer to have a motor with reverse. Older Grummans have a thicker hull than the new ones. Mine is rated at 1100 lbs. Good reviews on the Alaska Outdoors Forum of both Grumman Sport Boat and Grumman 19ft freighter canoe.

Here’s the new to me trapping rig

Paid $1,600

looks like a great purchase. hope you get alot of enjoyment out of it in the seasons to come.

I think you'll like it, alot.

Love those old Johnsons. About as simple to work on as they come. Can be torn down and reassembled while on the water if need be.

Good choice considering the tailer went with it.
Have a look at the condenser coil and look for any swelling = if so replace. They had /have a problem not being used
the water pump is probably dry as well
looks like they had night running lights
and it must be a old photo with all those bluebills lined up

Yeah that photo was from earlier this fall before they moved south from Bemidji

^^^True^^^
You just can't beat an OMC twin. Points set at .020 and the 6J6 plugs gap at.030. That and install a new water pump impeller every 2 or 3 years and you're good for the water. That motor takes a 3/16" shear pin. I buy 3/16" brass rod and cut them to size.
TONS of spare parts and spare props for sale on E-Bay for that motor. You're running the river; get a spare prop. Doesn't have to be a new one, just a spare. When I'm running skinny rocky water I put on a pretty sorry looking prop and save the better prop(s) for deeper water.
If you'll move that gas tank to the very front of the boat it'll help you out on weight distribution in the boat. The more weight forward the better.
Go to the auto parts store and get some 3/8" gas hose and extend the gas line out. The fuel pump in the motor won't have any problem pulling gas that far.

Grumman Sports Boat and a 6hp OMC; you won't find a better matched rig and one of the most versatile rigs on the water IMO.

That is a great looking boat. I think you'll like it.

Very nice rig. Also think you will be happy.

I always liked keeping the fuel can up in the bow of the boat on my smaller boats but I have a 13 year old to put up there now, I should be balanced better now than back when I was alone