Any of the low-end Wacom tablets would do the trick, and you don't need the current model. Previous to the move to "everything is an Intuos now (and the Intuos all become Intuos Pro because 'Pro')", that would have been the Bamboo Creative, and before that the Graphire. All of them are well more than good enough for the task at hand, and if you can pick up old stock (or used) cheaply, go for it. Note, though, that if you've never used a tablet before, it'll take a bit before your movements coordinate - I've always suggested trying to live as much as possible using the tablet in lieu of mouse or trackpad for about a week. Once you've got the knack, it's pretty much with you for life, but it's easy to give up in frustration when you're not used to absolute positioning that's remote from the screen until the moment it all just sort of clicks.
