E350 Quigley Agile RIP kit - which Fox shocks to select?

[PBM4085]

Hi all, I know there is a ton of forum history but tried a search and didn't seem to turn up my exact question. Looking to buy the Agile RIP kit for 2013 E350 Quigley RB passenger. Usage will be driven empty a good bit, some passengers, maybe light trailer here and there. Not converting to a camper. I called Agile to ask about the different shocks offered and the customer service rep said I need to do some measurements and didn't seem super educated on the E350 (I know they are more focused on the newer vans now) - my question is, if they have sold tons of these can't they just say which shock is the right one/length if you're buying their full kit with coils for this particular van? Wondering if anyone with experience has any feedback on which ones to get. Also certainly open to any additional feedback on the whole concept, planning to pair this kit with progressive leafs in the rear but need to figure out the front first to match the heights. Any intel is appreciated, thanks!