Anyconnect by default starts off with accepting both (prompt should show "enter PIN or Passcode"), then based on whether Passcode or PIN is successful, the preferences are saved on the preferences.xml file for the next authentication. After that the prompt should show either "PIN" or "Passcode".
More info on this here:
http://www.cisco.com/c/en/us/td/docs/security/vpn_client/anyconnect/anyconnect43/administration/guide/b_AnyConnect_Administrator_Guide_4-3/configure-vpn.html
For text and GUI customization's, you would have to change the customization file (I usually copy off to notepad and re-import back into the section) from then ASDM for en language. The location is here:
Configuration > Remote Access VPN > Network (Client) Access > AnyConnect Customization/Localization > GUI Text and Messages
Banner can be customized under the group-policy using "banner" command or using ASDM here:
Configuration > Remote Access VPN > Add/Edit Internal Group Policy > General Parameters > Banner