I have bought a good bit of wiring products from Stein and wouldn't hesitate buying an auto pilot from him. He has a wealth of experiance that may come in handy when you install the unit.
 
Buying TruTrak

Hands down the best place to buy a TruTrak is from SteinAir. You can't beat the service, price, or the great bunch of guys at SteinAir.

I bought everything for my panel from Stein, including wire, breakers and switches and I have nothing but praise for everybody I dealt with at SteinAir.

I only wished the local FAA certified avionacs repair shop on the field was half as good as the SteinAir bunch.
 
I bought my AP from Stein, even though I had to pay sales tax to do it.

1. They KNOW this stuff.
2. They make most of the commercial wiring harnesses and their color coded premade harness makes wiring a breeze.
3. Great service.
4. Competitive pricing. I doubt that they are the absolute cheapest, but they have really helped me, even to fix screwups, even when I caused the screw up.

Lots of low buck suppliers come and go in the experimental world...Steinair is here to stay and all the guys there are experts...most are former Airline engineers, and airline simulator engineers/techs.

JMHO