I would advise against a laptop if ergonomics are a factor, they are slightly better than smartphones but still overall bad. Get some basic PC setup (if you don’t want to build your own, I suggest an ASUS mini PC or mac mini) and spend the rest on getting a decent chair, a desk where the monitor and keyboard/mouse are at levels that are comfortable for you.
That’ll be fine. Just make sure you get a separate mouse no matter what your setup is to begin with. also you can get a laptop stand instead of a separate monitor, which will be cheaper while still improving ergonomics, though you will need to also get a keyboard