Of the choices the OP suggested, the Surface Pro is the way to go.
I have one myself and it's a true Wacom digitizer. The only way you are going to get a better experience is to go with a dedicated Wacom product. You can get a pen tablet like the Wacom Intous line, which would be less expensive but would require a computer and monitor, or go with a Cintiq. The Contiq companion is a full Windows 8 tablet and is available with a 13.3" 1080p screen.
All said, while the Cintiq will give you 2048 pressure level variations, the Surface Pro will deliver a respectable 1024 levels of pen sensitivity and a higher pixel density. Both are good choices but I suspect the refurbished SP will end up less than half the cost. Assuming that the OP is cost conscious, the SP would seem to be the obvious choice.