I say do it in a Dupli-Color Bedliner that comes in the rattle can. Great protection and won't really have to worry about chipping or rust. Or you can do rust-o-leum in semi gloss black. If you take your time and let the paint cure for about a good week before you put on the clear coat you should eliminate most chipping. Use some accetone or paint stripper to get off some of the old paint and gunk. Use a Adhesive Promoter or Primer and then spray it with the black then let it sit for a few days (IMO 5days is good amount of time. Longer the better) Then put on some 3-5 coats of clear and let it sit for another couple of days to let it adhere before use.
Looking for another Ranger for the GF
2006 Mazdaspeed6 aka: SLVRBLT Daily Driver
2004 Ford Ranger aka: URBNRNR SOLD