My boss has 2 E-350 vans w/ the powerstroke, I don't think that they are quite as good as a 1 ton p/u but I think that in your situation they would make a good choice. Avoid the extended versions, Ford just adds on behind the axle, not the best pulling a heavy trailer. I don't know what type of rigs you will be hauling but two rigs and a trailer long enough will most likely be maxing out the towing capicity. Remember that the weight of the wheelchair lift will decrease the cargo capicity of the van, try and keep it as light as posibile.
brewchief
brewchief