I have for sale a Class IV trailer hitch setup, that has until recently been used by my parents. I believe Valley is the brand, and it fits a 2" receiver, has a 2 5/16" ball, and is rated for up to 12,000 lbs.
It includes the spring bars or "load leveling bars" and their mounts, as well as all the sway control mounting components. The only accessory it does not include is the friction anti-sway bar itself, which my parents are still using with their new trailer. They can be purchased separately for $40-$50. This setup is capable of using a single or double anti-sway bar setup, and I can tell you that they really really help stabilize the trailer when towing, especially with a 1/2 ton pickup or smaller SUV. Effectively all the hardware is included, but the few components that actually mount to the tongue of your trailer could probably be replaced with new for peace of mind.
I believe this is the hitch as sold new:
http://www.southwestwheel.com/store/p-3515-va70230wdb.aspx
And this an example of the anti-sway bar available separately if you tow with a smaller vehicle:
http://www.amazon.com/Valley-75190-Sway-Control-Adapter/dp/B000CQ02B4/ref=pd_bxgy_auto_text_b
I've personally towed a 30' 9500 lb trailer all over the country with this setup, and I can answer about any question you may have about it, including how it works etc. for anyone not familiar with towing.
$125 I'm in Pickerington.
http://i180.photobucket.com/albums/x33/spankis/Stuff%20For%20Sale/IMG_0661.jpg
http://i180.photobucket.com/albums/x33/spankis/Stuff%20For%20Sale/IMG_0658.jpg
http://i180.photobucket.com/albums/x33/spankis/Stuff%20For%20Sale/IMG_0656.jpg
This is a picture of what it basically looks like when all hooked up, I didn't have the trailer at home to take an actual picture:
http://rvadenver.com/distri85.jpg
Thanks