the warn 16.5ti is a bad mother! i plan on mounting one on my truck once i finally get my ranchhand bumper in...been on backorder for about 7 weeks now, just becuase im having the hd winch option put on which is up to the warn 16.5ti.
i currently own a warn 9.5ti and had it multimount which mounts to your reciever and was nice becuase u could move it front or rear and i kept it in my tool box to save in lenght. but in most cases wasnt even enough power for my 1500. its on hard mounted on my jeep and is plenty for that light jeep. i think for a 3500 diesel a 12k is the least winch to buy but the 16.5 will work well.
as for bumpers, almost all your big name brands have an option for it, including ranchhand, roadarmor, warn, arb, buckstop, and many more.
btw the largest winch to mount multimount is the 9.5ti, at least for warn, heard something about milemarker making one on a 12k but im not all fond of milemarker, some of my friends havent had much luck with the solenoids.