Hey, thanks for the info, quite timely.
I started a thread 'Mexican FIX' relative to this exact issue.
My research came down to Monroe's, either SensaTrac or Reflex. Too bad they didn't hold up for you, maybe a warranty issue?
I'm running 10ply 80lb tires with Bilsteins right now and it's a kidney belt ride even on smooth pavement. My Hoe was my primary tow vehicle until I replaced it with a Touareg V10TDI. I'm changing out the tires this week. Spec for the vehicle is P245/75R16, I've been advised to go slightly wider at P265 to get a higher sidewall resulting in slightly more cush. I'll probably go with this and see how the Bilsteins perform. If they don't, which I don't think they will for the ride I'm looking for, (which dovetails with what you're looking for) I'll go with the Monroe Reflex as they claim "improved stability with reduced harshness". The SensaTrac claim "smooth ride with good control". They both sound good but the technology of the Reflex appears the most advanced to deal with the driving conditions I'll be dealing with.
My experience with the Bilsteins is that unless they are under a good load, they're stiff as hell. The Rancho's, I think the 5000 is the same as the 9000 but the 9000 is adjustable. Rancho's web site shows a graph of sorts indicating that the 9000 starts at OEM spec and gets stiffer with adjustment. At least that's how I read it. So I'd conclude that the Rancho's are gonna be similar to the Bilsteins.
Again, thanks for your post, it helps confirm what I'm trying to achieve.
Ed