Replacing Shocks - 09 EL w/air levelling

[quicker]

Guys,

Just trying to wrap my head around this. I have an 09 EL Limited with approx 200k on it.

Its has the coil-overs on the front and air bags/shocks on the back and has the auto rear air levelling.

I would like to replace/upgrade the shocks. Couple of questions:

1) Rear: can the shocks be swapped without replacing the air bag? Do they separate? If not then how do people replace rear shocks?

2) Front: when I look online for shocks (bilstien etc) the shock doesn't seem to have the bottom collar to hold the spring when installed. I'm assuming these are just stock photos and the specific model for my truck (24-197717) would have the bottom collar?

Also curious what your guys real world experience has been with aftermarket options? Are bilsteins noticeability stiffer? any other quality options? I do all on road and highway driving and a fair bit of towing the travel trailer.

Thanks

 

[Gruz7]

MOOG makes collars for the Expedition and they have nice constant rate springs too. I have not ever driven on bilsteins in and Expedition but, as I hear, they are a bit stiffer but really could go either way. But also, from experience, Ranchos are much stiffer than bilsteins, just something to think about.
Attempting to answer you other question, i would think that the air bag can be separated but it won't go back together how it should some either id buy a whole new bag system or just get some struts for the rear and ditch the bags.
For reference, i just purchased 4 struts, front/rear, from completestruts, its like an OEM shock and spring and i will be installed them as well as leveling kit and i am expecting i'll have a pretty stiff ride.