All drop brackets for an 4WD 80-96 F150 will bolt on to a 2wd F250 from 80-97. The brackets will break/crack easier though from the added weight. Aftermarket radius arms will work too. Giant makes equal length pivot brackets and LT kits for these.
If your going to keep it 8 lug with need to call Giant, Dixon Bros, or possibly H & M. I once saw a flyer from H&M that showed an F250 kit and I saw a Superduty with a Dixon kit. Anyones 2wd F150 kit will fit but with the added weight of a F250 who knows how long it will last. You will have to use 5 lug stuff with F150 based beams.