Get the Intuos3. Period.
Graphires 3 and 4 + Blender + Ubuntu Hardy/Intrepid works just fine for me. You probably have to edit the xorg.conf a bit (not sending core events by default), but all you need is in man wacom. I guess you can tweak modules and makedev as needed, but I didn’t have to do any of that.
I’ve been using a intuos3 4x6 and it works great. No complaints.
It might be nice to have the larger pad, but the reality is that you can click the button on the pen hold CTL and zoom in zoom out if you want the closer control… and really it is about half the price of the larger one.
The bambo is fine but lacks tilt for drawing, and its resolution is much lower.