I am thinking of buying a kayak for fishing for smallmouth but am concered if i can fish all day without back bothering me. my other choice is a pelican 12ft jon  boat HELP!

Get the jon. Its bigger and more stable.

I started trying to fish out of a plastic sit-in kayak and found it tolerable for about 1 hour. Putting a pad under the seat helped but raising the center of gravity made the boat unstable. A sit on  kayak was out of the question as I fish in cold water and don't want to wear a wet suit to keep warm. So I think the jon is your best bet, more stable, higher seats and dry.

I finally decided to make a boat that better fit my needs. Its is warm, dry, about 80 lbs and controlled with my feet, leaving my hands free to deal with fishing gear. You can have a look, just type into your browser jimskayak.com

I will agree that yes a jon would be better than a kayak. If you have the means to have a traler, and money than u would be better off with the jon IMHO.

I however will be fishing from a kayak for my second year. I have a pamlico wilderness systems 120 and i can sit in it all day long and fish. Only time i need to get out is to take a leak. If you get the right model, with the right seat its well worth the extra money. Wilderness systems have some really nice seats, as well as old town in there higher end models. Kayaks have there advantages over larger boats...and vice versa. For example last year me and buddy were on a 2 day fishign trip on a river for smallies....there were some guys on the river doing pre tourny fishing. All 3 guys we were talking to were having bad days as far as the amount of fish they were getting in the boat. We were having a great day, but we were able get our yaks into waters where the fish were, and the larger boats could not get.

Good luck with whatever you choose  

Some can fish all day from a kayak without a back problem.  But, it's not the case for everyone.

Some swear by kayaks, others swear at them.

My preference would be the jon boat.

The kayak is easier to launch and transport to launching sites were you cannot get a vehicle close to the water.

You can take more gear comfortably in a jon boat, and the seating is better for folks with back problems.

Pros and cons to each.  

Some can fish all day from a kayak without a back problem. But, it's not the case for everyone.

Some swear by kayaks, others swear at them.

My preference would be the jon boat.

The kayak is easier to launch and transport to launching sites were you cannot get a vehicle close to the water.

You can take more gear comfortably in a jon boat, and the seating is better for folks with back problems.

Pros and cons to each.

What he said  

Thsy make back support seat for some of the models of Kayaks

Why not split the difference with a canoe?

I fish off a kayak exclusively, as I don't my have money, time, or means to move and jon around.  I love it but my back and @ss do hurt after a few hours.  I love the convience and the ability to launch almost anywhere.  I picked up a hobie sport, it's amazing.

Everyone else has summed it up well.  There are certainly pros and cons to both options.  I have fished out of a sit on top kayak for years now and love it.  It works great in in a ton of different places and is relatively easy to launch.  It will make you sore after an entire day of fishing.  As for the gear, the jon boat loaded on a trailer will definately be simpler in that you don't need to load all your gear every single time you go.  If you load the kayak on top of your car like I do, then every single time you put in or take it out of the water you will need to load and remove your fishing gear.  Even in the kayak I carry several rods way more tackle than I could ever possibly use.  Including drinks, snacks, and essentials.