A lot of guys do the Bilstiens. Many say loaded and/or towiing they are great. Empty, not so much. Fox 2.0 seem to be the new darlings of the truck world. Kinda spendy but many say they have a good ride loaded, towing, or empty. I like the Rancho 9000's but that's me. Stock shocks are not that great. Yeah focus on must haves like upfitter switches, gears, backup camera and/or other essentials. FX4 is not essential IMO.
If you're looking at a 17 F250 gasser, you get the new G tranny (6R100). It's a beefed up version of the tranny in a F150 and is said to be better matched to the F250. It's lighter and geared a touch taller so better for MPG's. A F350 gets the full Torqueshift 6R140 which appears pretty bulletproof regardless if it's gas or diesel. It's got lower gears and is big. Maybe you lose a little MPG's but it's hard to say. One reason I went 350 was I wanted the biggest and bestest tranny I could get for my use and situation. The G is new so the jury is still out but it should handle the F250 fine. The 6R80 in the F150's have been good with not too many issues as far as I can tell.
It should be noted a F250 Diesel doesn't get the G. It gets the same 6R140 as the F350/450
2022 F350 DRW Lariat Ultimate CC, LB, 4x4, 7.3L
2005 FWC Grandby
2023 Rockwood 2720IK Travel Trailer