If you are talking about pontoon boats, there are lots of options.For really knarly white water I would spend some money and go with pontoons with welded seams and multiple air chambers per pontoon.I've heard some people complain about the pontoon styles that have an air bladder with the PVC outer covering. They say that gravel will get in between the two and cause abrasion.
I have a 9ft built by Outcast that has air bladders and have never had a problem.It cost about $500.My Outcast does not have welded seams either. The Outcast boats with welded seams come with a ten year warranty I think. My boat has adjustable foot pegs and they work fine.As far as 10ft vs. 8ft, that depends. I weigh almost 230lbs and the 9ft floats me pretty good.One of the reasons to have a raft vs. a hard bottom drift boat is they are easy to launch and carry around.I have a friend who has a 10ft pontoon boat made by Bucks Bags.We were floating a local river a few weeks ago and came upon some sweepers. I lifted my boat up with one arm and carried it around( it weighs about 40lbs).I had to help him with his and I think my drift boat is easier to push than it was to carry that thing. Of coarse he has everything but the kitchen sink attached to it.
Anyway, I hope this gives you some info. Also, I ordered my boat from Anglers Inn out of Utah.