I don't have one but would like to have one that includes the slow treadmill.
I have raised my monitor by putting a PDR (big pharmacy book) under it. I can put box under my keyboard and stand for a while. That helps.
I've just recently been working without articulating arm supports (2weeks) after many, many years of using them. Had to put the left one back on for a while. I'll have to get stronger...
I've also placed a long dressing mirror at the side of my work station, as a posture monitor. That's really helped me a lot too.
I also use oversized tennis balls for my lumbar back.
Have had vibrating/massaging chairs and other supports from time to time.
I find you need to change things as time rolls along so I don't like to put a lot of money into it as I have changed my needs over the years.
Try modifying with some thoughtful ingenuity before you buy. I have bought a lot of things to help... reachers, grabbers, desks, stands...
I need to alter sit/stand, or just walk around and do something else for a while. it's never a pleasant interruption... aggravating is more the word.