I use a simple WACOM Bamboo. Not the touch version. Was about 90 dollars new about 2-3 years ago. I think they may have discontinued the product line

Its not plug-and-play per say, it came with install CD but believe the drivers are available online.
A bonus is when I first got it, it came with a free software ArtRage. Got me started on colouring before I bought SAI for about 50 dollars. You can source it for free, however...

I haven't tried other models, but the bamboo syncs with the computer screen. Touching the corner shoots the pointer to the corner on the display. Bamboo are not built- in screens so its a little practice to get used to "drawing blind"

The line was renamed to Intuos at some point. Is the small touch area ever an issue?

Not when you zoom in so much :P

I have 8GB of RAM on my system, so can use 5000x3000 canvasses all the time. 4GB systems might struggle a little, so you may have to dedicate yourself to drawing on those 4GB, or work on say 3600x2250 canvasses (3x as big as FA size limits for length)

Intuos was the Next-Gen stuff... So I guess it was just replaced. You may get rather inexpensive Bamboos though.