E450 Rear Brake Pad Replacement - long post w/pics

My plan was to pull the rear and front calipers, clean and re-grease the pins, and put new pads in. Then bleed and flush the system. The RV has about 23000 miles on it but had been sitting awhile before I bought it. The brakes seem to work ok but they do drag a little. It this a good plan and sequence or??
Also is there a recommended replacement pad or will anything for a 2004 E450 super duty work?

Thanks again for all the info.