I’m another Dvorak/Kinesis user (I actually have the Switchable Dvorak Kinesis model) and I’m quite satisfied with both.
On Dvorak: It is a better layout, but that month of learning can be pretty rough. I’ve found it has sped me up a little (though I’m not an ultra-fast typist), and I do think that the lessened finger-movement could make a difference for RSI—I learned Dvorak preventively for this reason. It’s very easy to use in any operating system (without any hardware), and I’ve found I can also use Qwerty now without much of a problem. Colemak sounds intriguing, but I can say that cut and paste and everything like that works fine on Dvorak (VIM was the one exception… that took some config).
On the Kinesis: It is a great keyboard. But I wouldn’t worry about getting the Dvorak version that I have. As Bob said, when you learn to type Dvorak it will be in your head (and you shouldn’t look at the keys anyway), I find little benefit in having Dvorak on the keys. (When you’re learning, you can just use cut-up post-it notes on the keys, but going mental is best). But I do think the Kinesis is an excellent product. I still use my laptop often without it, and I have no problem switching between my Macbook Pro’s dvorak layout and the Kinesis Dvorak (some of the symbols are in different places).
People are often borrowing my computer, and they are always confused when they begin to type. Be prepared for that.
Given that you have some RSI, I would recommend trying the Kinesis. Dvorak is more of a lifestyle choice, but it may help you, and I’d recommend it if you have the right attitude and sufficient time. Good luck!
Also—I think taking breaks is key, and never typing when you feel pain.