For a text-input box for username - try the elarun or maldives themes And fwiw - for a single-user desktop - I use auto-login (I wouldn't do this on a laptop - or if I thought anyone else had physical access)
[Autologin] # Autologin again on session exit Relogin=false # Autologin session Session=plasma.desktop # Autologin user User=myusernamehere
