I use a Rikon Mini lathe, it is about 10 years old, never had a problem with it. 12' inch swing, 16" working distance between centers, speed from 430-3900 adjustable via belt. I have turned everything that I ever wanted to on it.
Also...I turn everything at 430rpm, never saw the need to go any faster. Keep you tools sharp.
A 1/2" Jacobs chuck, an adjustable 4 jaw chuck and a Pen turning mandrel will help with your horn turning.
Tim C.