James,
I don't believe Trail-Air makes a hitch. They do make a Pin Box as attested to by BluegrassMan and I have heard they are very good. But air pin boxes and air hitches are two different animals.
I have been researching Air Hitches. The two main companies I have found are the TS3 by Hensley and the Air Safe Hitches. Both are loved by their owners from the e-mails I have received.
Air Hitches are more expensive, currently around $2500, but they are not that much more if you have to buy a regular hitch and then buy the air pin box to go with it. Most of the people that have responded to my e-mails on rv.net forum have bought the 25K lb hitch instead of the 20K hitch. If you decide later to get a larger trailer you don't have to buy another pin box for the new trailer - thus saving you a lot of additional money.
The other opinion of air hitch owners is that an air hitch is the smoothest ride available since the whole pin floats on air. One e-mail I received said, "I can look in my rearview mirror and see the trailer moving on the hitch, but I can't feel it."
Go to rv.net and do a search on "Air Hitches". You will get a lot of posts to read.
I will probably order my air hitch tomorrow to go with my new Bighorn on order and my F-350 on order.
Good luck !