I'd second Bob Briehl of Appalachian Instruments.
I purchased an Autoharp from him over 2 years ago, and though I bought close to top of the line (An OS110FGN - fine tuners, 21 chord, plus added a pick-up), he let me try out several models when I went to visit him, and I got to get a feel for what each instrument was like.

I knew nothing about them when I bought, other than research I had read, but I am glad I went to him and got the best I could as I have certainly grown into it now!