Pbb321

You could also try your hand at some scripting as well...

C:\Windows\System32\cmd.exe /k %windir%\System32\reg.exe ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /t REG_DWORD /d 1 /f

this is the command to enable UAC. The only way i see this playing out is this...
Have this script run at startup. If your user does go in and disable UAC, it will require a restart anyway, which will force this script to run again.

As a last resort, depending on how much access your want your admins to have, you could go in to the policy for these computers and remove the "User Accounts" option from the control panel.