My husband turned my Bailey Pro 15 into a sit down machine. I love it so far I have quilted 3 twin size quilts on it. And one day soon a king size. I don't anticipate any problems. My machine sits in a rather generous size table.
I found it difficult to stand for long periods of time also. As far as my stitch regulator/speed control. I used double sided tape and a small piece of wood to set how far down I can press the pedal down.