What is a good/better/best tablet computer to use with Corel Draw 12?

At the small rural school where I work we send vector drawings from CorelDraw to our laser cutter, which does a great job in cutting out the drawing in wood. To get the vector drawing we usually scan an image, clean it up with PhotoPaint, convert it to vector with CorelTrace using centerline, clean this vector image up with CorelDraw and then send it to the laser. The scanning, cleaning up, tracing, and cleaning up again process is cumbersome;  especially the centerline tracing process that creates lots of little lines that need to be deleted, straightened, etc.

I've experimented with a couple of tablet PC's, a Gateway and an Asus, with mixed results. I put the scanned image on one layer, then on another layer I traced it using the tablet pen. When this works as I want it to I quickly get a vector image that is ready for the laser. However the Gateway was hopeless, the pen did not work well at all. The Asus was much better but not as accurate as I would like. Maybe there is a tablet PC that someone uses in this fashion with CorelDraw? I've been looking at reviews of the Toshiba 700 and the Dell Latitude but nothing in what I read addresses this question directly.