I got a Hidden Hitch Class III/IV for my old '05 Trac. I just bought it at a local truck accessories shop. Tucks nice and close to the bumper. Whatever you get will cost about $120 to $140 but I think Hidden Hitch is top shelf.
For an ATV trailer I would just use the bumper hitch, you only have buy proper ball. I have pulled a 2 place quad / snowmobile trailer and an 18 foot inboard boat on my bumper hitch on my 02 ST for years with no problems.