You can run Sambapos on any tablet on which you can install a RPD app (remote desktop protocol). You have RDP apps for Android and for iPad.
When selecting a tablet I would look for quality of hardware design (does it react well on touchscreen), and for the right size. The larger the tablet the better the information will look on the screen, however if the staff needs their hands for other things (like cleaning a table), they must be able to put it away. A large tablet won't work well in this case.
I tried Sambapos on a cheap tablet, and it was not workable because the touchscreen didn't respond well.
