I bought a 23" touchscreen monitor about a year ago to try to use with sonar and plugins to alleviate my wrist issues caused by leaning on the mouse all day.
Have you tried any tennis elbow exercises? They usually involve wrist flexion. The elbow, wrist and associated tendons are all connected and usually problems with one coincide with problems with the other. Of course I don't know what the specifics of your wrist problems are, but I do know that regular wrist flexion and strengthening exercises can help people who have conditions caused by excessive mouse usage.
One that I do every day is this: hold the arms out in front of you at shoulder height, fists clenched lightly, palms facing down. Bend the wrists downwards as far as you can stretch, and hold for a couple of seconds. Then bend the wrists up to full extension and hold again. Repeat this 10 times. Next, twist your arms so that the palms are facing each other. Perform exactly the same stretches, but rotated 90 degrees.
This does wonders for the wrists, forearms and tendons. In fact it works as a cure for tennis elbow for a lot of people. There is also something you can buy called the
Flexbar, by Theraband. You perform a very specific twisting and untwisting exercise with it (there is a video somewhere on YouTube) which virtually guarantees a cure for tennis elbow (and associated conditions) in just a few weeks. Very good for the wrists.
I know what it can be like to suffer wrist and tendon pain, especially with mouse use. I once saw someone using a mouse that was held vertically, i.e. with the hand in the beer can holding position, which is apparently a far healthier and more natural position to use a tool. Never found out where to get them though.