A fuller set you can use
http://www.voip-info.org/wiki/view/Asterisk+Detailed+Variable+List
particularly
${VM_CATEGORY} * Sets voicemail category
${VM_NAME} * Full name in voicemail
${VM_MAILBOX} * Mailbox Number
${VM_DUR} * Voicemail duration
${VM_MSGNUM} * Number of voicemail message in mailbox
${VM_CALLERID} * Voicemail Caller ID (Person leaving vm)
${VM_CIDNAME} * Voicemail Caller ID Name
${VM_CIDNUM} * Voicemail Caller ID Number
${VM_DATE} * Voicemail Date
${VM_MESSAGEFILE} * Path to message left by caller
There is no guarantee that VM_CALLERID, VM_CIDNAME and VM_CIDNUM are useful, it depends on your provider specifically if they send you reliable Caller*ID and/or CNAM ( and you ultimately if you post process with whatever 
) .
To be explicit, VM_CALLERID = '"VM_CIDNAME" <VM_CIDNUM>' so one or both or neither will be useful.