.....edit... You should be able to get the tow package on the v6 access cab with convienence. It includes the hitch, wiring, trans cooler and upgraded alternator. def worth the $399. If you buy a hitch alone, it is roughly $300 without any of the other upgrades.
No tow package available for convenience pkg. Maybe it's a Southeast Toyota thing? (the V6 Tow Pkg is $650)
Cut and pasted from SET build site:
V6 Tow Package: cannot be selected until at least one of the following is selected: TRD Sport Extra Value Package, SR5 Extra Value Package.
V6 Tow Package:
Includes: Class-IV Towing Receiver Hitch, Transmission & Supplemental Oil Coolers, 130A Alternator, Heavy Duty Battery, 7-Pin Connector w/Converter, Trailer Sway Control.