If you want to try something kinda unusual, here's what I'm doing. I have a sit stand desk, and I have two different chairs. A saddle seat and a drafting chair.

If you want to try something kinda unusual, here's what I'm doing. I have a sit stand desk, and I have two different chairs. A saddle seat and a drafting chair. The saddle seat is very good for posture because it opens the hips up and increases the angle from your legs to torso, which makes sitting upright much more comfortable. However, I can't sit in it for more than a couple hours (maybe I'll adjust over time), so I switch between either standing or sitting in the drafting chair. The drafting chair is great because it goes super high so you have a lot of different posture options with an adjustable height desk. I think any solution that involves being in the same posture for too long is flawed, so variety is a good idea to keep your body happy. I think I spent about $250 on the saddle seat, and $150 on the drafting chair, so it's a pretty cheap solution that offers a lot of flexibility. I made the desk from a full sheet of plywood cut in half, finished smooth, and glued together to make it thicker and some electric legs I bought for $250. All in about about $700 for the desk and two chairs.