Floor supports

What do you guys think about this for replacing the floor supports.
Would 2x2 square tubing cut in half work for this? Would it be strong enough? Cut down to say 2x .5 or even 2x1? And use round tubing for bolt supports?
Also which way should I mount the supports? l_l or the other way?

Tim, the channel will work, you would want the open part down to avoid building a water trap. I ususally just use 1" X 1" square tube for a floor support, the seat support braces I usually build them out of 1 1/2" X 1" rectangular...

Thanks Dave.

i built my buckets floor out of 1 inch sq light wall tubing and framed it into a center tunnel it worked great and really strong just a lot of welding :) :) :)