Chairs are like beds. Locate a GOOD Office supply, Office/ furniture supply. Try...Try...Try.... Does it fit, does it adjust, just it work for your back, neck, arms. If your going to use this chair for hours on end, you will quickly find a chair that doesn't fit, will leave you with back pain, neck, shoulder pain. Even check the large city upscale office supplies and check out the chairs. You can then know what you want and shop for deals.
You can either modify or go with the height of the scroll saw. Also know if your going to get up a lot for supplies or needing to grab tools or move projects. A bar stool type is easier. Sitting with feet flat on the floor my ease back, leg, foot pain. RJF