I just bought an office chair from staples. It's pretty comfy BUT it was too short, even on the highest setting. They're all about the same height, I guess. I tried using a thick pad on top and it didn't feel very stable or comfortable. So I bought bigger wheels for it. It made it a couple of inches taller but I could use another inch or so, so I think a thinner cushion might be the thing. The wheels on my sewing cabinet are already pretty small so I don't think I can lower it any.