None of them helped. Surprisingly the thing that helped was getting a really good chair (I recommend a second hand HM Mira; don't get anything that sells itself as "ergonomic"), and a really deep desk so you can properly rest your forearms on the desk.
With that my RSI went away completely, even with a totally plain qwerty keyboard.
Dvorak was definitely nicer than QWERTY but when you add up...
1. You know qwerty. You'll probably never be as fast with Dvorak.
2. Ever want to type on any other keyboard in the world again? Yeah good luck. You will underestimate how often you type on coworkers' keyboards.
3. Ever use keyboard shortcuts? Well now they're awful.
... it definitely isn't worth it.