Personally, A5 is the size for me. I have used everything up to a 17x12,...not sure of that exact dimension, but it was close to that.
Anyways, anything 12x12 and up means you will be drawing from the elbow with large movements. Smaller sizes mean everything will be mostly finger movements, and the A5 size will allow you to draw with the wrist and fingers. It depends on what you are comfortable with.
My current setup is a dual screen, which is too wide for even a "wide" tablet. Normally I simply work with one tablet on the left, and use my mouse when I need to reach a menu on the right side. Another thing I have done is plug 2 tablets in at the same time, and map 1 to each monitor. This works great, but take up too much desk space for me to use all the time.
The latest Wacom drivers have an option that lets you change the mapping of the screen with a button. I set one of the tablet buttons to do this so I can now control both screens by toggling back and forth.
Anyways, anything 12x12 and up means you will be drawing from the elbow with large movements. Smaller sizes mean everything will be mostly finger movements, and the A5 size will allow you to draw with the wrist and fingers. It depends on what you are comfortable with.
My current setup is a dual screen, which is too wide for even a "wide" tablet. Normally I simply work with one tablet on the left, and use my mouse when I need to reach a menu on the right side. Another thing I have done is plug 2 tablets in at the same time, and map 1 to each monitor. This works great, but take up too much desk space for me to use all the time.
The latest Wacom drivers have an option that lets you change the mapping of the screen with a button. I set one of the tablet buttons to do this so I can now control both screens by toggling back and forth.