I went with Koni FSD shocks on my '2012 Chevy Express 3500 based Airstream Avenue Suite. Pricy, but very satisfied with the ride and control on uneven, twisty roads. Got them through shockwarehouse.com.
Went with the FSD's because the are NOT gas-charged. I hoped this would provide a smoother ride over small bumps and road irregularities, yet they promised ride control damping over larger uneven road surfaces. They have performed well.