Increase mouse pointer speed
You need a to buy a mouse with a higher DPI in order to have speed and accuracy. I have a very similar setup: 24" monitor and 22" monitor I had to upgrade my mouse because I could not find a good balance of speed and accuracy with my old one. I went with a laser mouse they have excellent accuracy. This is the mouse I bought, I know it's a little pricey but trust me the extra money was worth functionality I got from it.