I have a Horn chair. Sorry, can't remember what I paid for it.
I have very short legs. When I adjust the chair to the correct height so that my arms are positioned at a 90 degree angle, my feet won't touch the floor. If I lower the chair so that my feet are flat on the floor, I have to reach up at an angle to reach my machine. This causes a lot of stress on my shoulders.
My husband built me a very nice platform that slides into my horn cabinet to rest my feet on. My foot pedal also sits on the platform.
Mine does not have arms and has has 5 good sized wheels. I also bought one for my son for Christmas one year that he uses at his computer. We both love ours. But, it does pay to try out the chair to find the one that suits you the best.