Evoluent Mouse-Friendly Keyboard
You can type, mouse, and use the number pad all while keeping your arms relaxed and close to you.
Ordinary keyboards have the numeric pad on the right side. This forces you to place the mouse even further to the right. When you reach for the mouse here you place undue strain on the neck and shoulder.
The Mouse-Friendly Keyboard has the numeric pad on the left. This allows you to keep the hand right in front of your shoulder in a neutral position while you mouse.
This keyboard is a good option if your wrists do not bend outward at the wrist while you type. (If your wrists do bend toward the little finger while you type consider one of the split/angled ergonomic keyboards.)
This is designed for low to moderate numeric pad use, if your job consists primarily of number input this keyboard may not be ideal for you.

