If you mean a roll-back flatbed wrecker/recovery bed, or what the industry calls a carrier, then you usually won't find them on "little" trucks like the F-350. The F-550 is about as small as they make new with roll-back beds, and most of them built today are at least a Class 6 truck (F-650 or equivalent medium-duty truck).
Jerr-Dan, Champion, and the other major wrecker manufacturers won't install a roll-back bed on a '99-up F-350. Not enough payload and not enough CA for a loaded roll-back. You have to have a GVWR of 19,000 pounds, so most folks that want the smallest possible Ford now go with F-550 regular cab, which has an optional 120" CA and 19,000 GVWR made especially for the rollback market.
Jerr-Dan's minimum requirement for the truck under their rollback:
Recommended Chassis Requirements
GVWR: 19,500 lbs.
Rear GAWR: 13,500 lbs.
Jerr-Dan® Corporation : Carriers : Industrial
The F-550 has the 13,500 rear GAWR, but only 19,000 GVWR. IOW, they don't want to mount a rollback on an F-550, but they'll be glad to mount it on an F-650.
Weldbuilt also makes carriers.
TB100ST Steel Carriers
Their least-expensive rollback bed is "Suitable for 18,000 lb. – 21,500 lb. GVW chassis". A normal F-750 has only 17,500 GVWR, but Ford makes it in a regular cab long wheelbase rollback special with a GVWR of 19,000 pounds.
But if you insist on trying to mount a rollback on an F-350 - and can find a bed that will fit on a pickup frame - then the first step is to have the PTO prep option on your automagic tranny. If you have an automagic tranny without the PTO prep option, then your first step is to replace the tranny with one that has the PTO prep option. That option is nothing more than an access plate on the side of the tranny, but you need that access to add a PTO.
After you have the right tranny, then you need a PTO and a hydraulic pump system with storage tanks for the hydraulic fluid.
The most popular PTOs are Muncie and Chelsea. Muncie is at
Muncie Power Products: Power Take-Offs, Fluid Power Products, Hydraulic Components
Chelsea is now a division of Parker.
Chelsea Products Division - Parker
Either one of those makes all the PTO, hydraulic pumps, lines, and tanks you need. Most are installed by a local Munci or Chelsea upfitter.
Your 2005 6.0L has a built in idle controller, but it has to be wired up right to work with your PTO. It's called the stationary elevated idle controller (SEIC). Do a search on SEIC and you'll find instructions on how to wire it up to work right.
After you have the PTO and hydraulic pump installed and working, it's time to mount the roll-back flatbed body. I don't know that anyone makes one for a pickup. Most are made for very-long wheelbase F-550s or bigger chassis cab trucks. A pickup has a lot different frame than a chassis cab, so if you find one from a chassis cab, it won't fit on a pickup without a lot of fabrication and learning new curse words.