You will need one or more Customer Stations, called Kiosks. These are made up of three things:
Brateck make good secure tablet stands. Here are two options:
Open "Industrial" style
Enclosed "Professional" style
Physical keyboards are optional, but help speed up the sign in process
Unbranded tablets usually have a separate charging port as well as a USB port, so you can use a standard mini wired USB keyboard with them.
Most branded tablets only have one USB port that will be used for constant charging, so you will need a wireless bluetooth keyboard with them.