At home I use a Macbook Pro.

Because of the RAM cost rises and desire to run LLMs locally, I have considered a mac mini or some other desktop mac instead of upgrading my macbook pro. (Since loading it with 64GB of Ram now has a purpose is probably didn't for me before.)

The most important thing for posture is to have a good office chair (herman miller Aerons are cheap used) and lift weights at the gym. A regular deadlifting (once per week) builds a strong back and core and keeps your posture in check.