Sounds like you need to go into the registry and set the device to think its natural state is Tablet Mode. Not something I've tried, but you could start by looking here...
http://stackoverflow.com/questions/3...at-i-last-usedTablet mode settings are found in the registry under [HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\ImmersiveShell]
The two important keys for you are TabletMode and SignInMode (you may have to create them).
0 = Off
1 = On
0 = "Automatically switch to Tablet Mode"
1 = "Go to the desktop"
2 = "Remember what I used last"
The user still has to type in information either on the screen or on a keyboard, hoping that the OS does not lock up or crash on them.
If you do want to do this, then use real tablets with Blue Tooth Keyboards. Then have someone actually write the software for say Android for them to use to do stuff. Laptops or combo's like the Surface get hot and require a lot more electricity then say a Samsung large screen tablet.
If you do not believe me about the whole touch screen and headaches in the vehicle, then you may want to schedule an appointment to talk to your local police department and have them show you what they go through and that the systems are set up that they are running specialized software on Windows 7 or even with Linux as the OS.