Those things seem to be hard to find. We've been considering trading pickups later this summer so I've been looking to see what's available. We need a 3/4 ton with 4 doors and a long bed. The 4 doors are easy but in new or lightly used pickups, I've only seen 1 available with a long bed. It was a Ford F350 with a 6.2.

Check with dealers who handle a lot of fleet sales. They tend to order pickups outfitted with the 8' bed and many of them have decent comfort packages. The last crew cab long bed I bought came out of Texas; I just flew down and drove it home.

Back in 1998, I bought a 3/4 T Ford, extended cab, long bed.I asked the sales person if Ford was ever going to come out with a short box.He said they would never sell.Now that is all you see. That long bed ford and a 20 ft gooseneck took 5 acres to turn around in.Even the truck itself could not do a U turn on a 6 lane road using all three lanes in the other direction

I don't need a long bed as I mostly used my truck to pull a goose neck.However, things changed and I went to a slide in camper and 3 horse slant bumper pull as I got older.Still a 4 door with long bed is way too long to get turned around in tight places. I do need the extra cab,but I went with the double cab which is about 6" shorter than the crew cab.
My slide in pop up is 6'-6" and Chevy's short bed was long enough. Dodge cut their short box down even more to about 6"-2 or 3".

I see a few long bed,with 4 doors, but most are std cabs around here.

There are 2 things I haul that require a long bed. I load my 50" Razor which fits in nicely. Then during hunting season, I load a stock rack to haul llamas and pull a camp trailer.
I have a diesel now but don't haul enough weight to need it. It's nice to be sure, but for me it's not worth the expense.

Cars.com is your friend.

You can filter right down to what you reallu need.

RAM.

Car.com has a deficiency in that they don't give a bed length, at least not that I can find. You have to scroll through their photos hoping they'll show a side view. It does stick to the 100 year old Ford motto though: You can get any color you want as long as it's black white.

in the used Fords a pretty fair amount of long boxes show up in these parts , most of which are diesels

I'll never buy a short bed. Made that mistake once and will never do it again. My current truck is a 2020 F250 crew with 8' bed. The newer fords seem to have a better turning radius than the older ones.

I have to have a long bed. I haul llamas in an 8' stock rack and my RZR fits in one, too, although the tail gate comes 4" short of closing. I have to tie it shut.

Every one I know who went from a 8ft box to short box regrets it. I have a RAM 4 door with long box. My wife dislike driving it in town, but it really isn't that bad. Says it's difficult to park. Heck she parks the suburban crooked so I wonder if its the pick-up or...

My long bed is also a Ram 4 door. It's a shade over 20' long so it won't fit in any standard garage. It has a huge turning radius. In town, I park it at the back of parking lots. I need the exercise anyway.

There is a long bed 4 door RAM new in our town. Just one and white. $66,000

I'd be looking on Autotrader.com myself. You can specify anything you want. Lenztruck.com always has 800 trucks on their lot and will ship anywhere in the country. I went from an F-150 8' regular cab to a 6 3/4' Super Cab to a 6.5' four door Super Crew. Sure it takes a bit farther to turn it around, but once you have the wind broken with the front of the vehicle, it doesn't matter if you are 19' long or 20' long. It isn't my daily driver, so that size works for me and rides better than a short box. You can put little stuff in a big truck, but you can't put big stuff in a little truck.

A huge turning radius? The 98 and earlier Ford's were the worst and the 99 to 2004 weren't much better.

Dave Smith use to have the best prices, I don't know if they still do.

I am the opposite,I'd never buy another long bed unless it was a 2 door.I have trailers to haul anything I need to.My last experience I had was with a 85 ford dually, extended cab. Took a few acres just to turn it around. Hell in traffic and hook a 20ft gooseneck to it and you are severely limited to where you go. Forget maneuvering a big bumper pull. Stick that 20 ft gooseneck on a short bed and you can almost turn it it around on a 2 lane road.Only draw back is that gooseneck will come around mighty quick and sure ding the truck cab if you are not careful

There are fifth wheel hitches that slide back preventing the trailer from contacting the cab of you pick-up. I forget the brand I saw, but they work pretty slick.

I have seen them for 5th wheel but not gooseneck

Ditto.

Had an extended cab w 8’ bed. I think wheel base was close to current super duty 4 door w short bed.

I would hate to be turning around even my GN (29’?) on a long bed.

They make a couple different options for a gooseneck. B&W Extend-a-goose

B&W Extend-a-ball

Those look pretty neat.Wish I had one when I was pulling mine