Jessup Chevrolet is a dealership in the Palm desert so I doubt financing is a problem...the OP might be the owner? The Express is the last body on frame van on the market, and I'm glad to see someone promoting it as a good SMB platform.
Glad you built it with the last year of the monster 6.6 Duramax. The 2017 has a 2.8 diesel out of the Colorado with a 25% reduction in power and torque...great for plumbers and electricians, but not so much for a heavy SMB.
The Transit/sprinter/promaster are all unibodies that, to me, appear to be soccer mom minivan designs built to 150% scale. Take a look at their suspension components sometime and compare them to an E series or Express. The interior size is impressive, no doubt, and MPG is higher.
GM should try harder marketing the Express/Savana to small fleet or individual tradesman, most of whom care more about uptime and ultra long term durability than interior space or MPG and the complex engines used to get it. I know a carpet cleaner with a fleet of 6 vans who ran his E350s for 4-500,000 HARD miles before replacing them. He is now replacing them with Savanas. Can the big minivans really hold up to that kind of hard mileage? Doubtful.
Love the build...can you post some interior shots? Curious how SMB outfits the Chevys.