After I installed my roll pan I had a frame-mount hitch installed. I didn't like the look of it so I went to the trailer shop and asked about a hidden hitch. Just the hitch was $300 (about 5 years ago), so I decided to keep my old one on. 2 years ago I had the hitch removed completely, no need for it any more (my truck is so low I had to install the ball upside down on a 6" drop hitch so it went up instead of down!).
You should be able to go ask any trailer or hitch place (I'd avoid installs by U-Haul, etc.). Just find one where you know they'll do a good job (look for hot rods in the parking lot
). Or, do it yourself!