Check the Arrow website, they make an adjustable table with electric motor for adjustments and it goes high enough to stand and sew. I think it's called the Tasmanian or something like that. As I recall it's pricy, but might be what you're looking for since you can adjust it with the sewing machine on it so you could change position frequently and easily if needed. It's large enough to put a sewing machine at one end and use the other end for a good sized cutting mat and ironing surface.
Rob