Since I've been mentioned couple times, I'll update y'all on where I'm at with the brackets....
The Cummins van got shelved for a little while to work on some customer projects so I didn't quite finish the bracket prototyping before the end of the year. I mounted the passenger side and it worked ok but the fit to the body wasn't as tight as I wanted it to be. Modified the brackets to make the fit a bit better and in the process discovered that making the running board fit the body perfectly meant that the brackets would cause the mechanism to bind a little. Meaning that the body and the frame are the slightest bit off from parallel and I made the brackets to work as if they were parallel. Not off by a lot mind you but "not a lot" over the 6' length of the board translates to a gap that I can't live with (1 deg over 6' translates to 1.25" gap at one end and zero on the other....not tidy IMO). So...I know what I have to do, I just haven't made new brackets.
Then there is the driver side... The same mounting locations can't be used for both sides so I need to redo the rear mount for the driver side. This will put the mount right in the middle of the cleanest space for mounting other accessories so it won't work that well for most already done up SMBs and home builds with stuff on the frame on the driver side. The two AMP mechanisms can be made to fit up front sort of close to each other and I could cut down the step a bit but I haven't even started looking into what that bracket will take to design.
Then there is the AMP parts...They're not cheap and AMP won't sell just the parts that are needed. You have to buy an expensive kit, toss aside part of it then buy new boards. Installation isn't technically difficult but to do it right would take several hours if not more. Some vans have so much stuff mounted on the frame that access to everything is a huge pain. If I had it to do over again, I'd skip these and go with a simpler design of step/slider. My wife just HAD to have them after seeing the SEMA van though.
I've had two vans come in to the shop that had the brackets from the Specialized guy. They're just 2" x 4" pieces of steel tubing with some holes drilled in them and cut at 45s on the ends. All the same issues with gaps and mounting locations apply though. You either have the room on the frame or you don't.
So after all of that, the truth is that I'll probably finish the set for the Cummins van since I have the parts already but that's probably where it will end. I think there is a better way to do this than with the AMP parts but unfortunately it's such a small market that it's not worth doing the R&D.