Just the fact that people unirionically ask this question these days make me feel uneasy. Your body is literally screaming at your to move more, not less, listen to it. Work in 30 min blocks and go for walks in between, anything other than "how can I become a passive typing machine which doesn't move a muscle for 8 hours straight" please.
There isn't enough money in the world to buy a setup that will get rid of these issues, just be active, that's all there is, if you know how to sit properly, take breaks and exercise regularly you could use a 5$ ikea stool and never have back/shoulder issues. People want the magic pill to be healthy but focus on all the wrong things...