I'm trying to find some kind of roof rack solution for a '96 Roadmaster.

Neither Thule or Yakima offer solutions for this particular vehicle, so I'm hoping someone on these boards might have some advice.

It does have the factory rack, but I'm uncomfortable using it to carry my mothers 100 year old adirondack guideboat. For one thing the spread needs to be much longer - ideally around 6'. The other thing being the guideboat has an unusual shape and needs to be elevated off the roof quite a bit (6-8") so it doesn't block the windshield.