Ok, sorry for the delay, but here's what I was able to come up with when I was planning to build a double rail raft frame. As a disclaimer, I never got around to building it because the deal on the rubber fell through.
: NRS sells anodized pipe by the foot. While not cheap, it was much cheaper than other on line metal places i found, its the correct size, and its already anodized.
: Unless you want to try your hand at tig welding anodized aluminum, you can buy all the fittings necessary to build up a frame. I believe the 1-1/4" pipe has an OD of 1-5/8, so those are the fittings to get. They come in T's, elbows, crosses, etc.
: You can get these from DRE, with the modified tower to fit the 1-1/4" pipe on the frame to the 1-1/2" oar tower.
From there, its just designing it how you want it. Not cheap, but you can make it the way you want, with an umbrella holder, cross bars for coolers, etc.
'97 lx450, 170k, factory lockers, ome 850/863, 285's, 4 working doors(1 more than the old fj55 )
'74 project pig (sold