The Strata DK40 does require the K5RCU DTMF card if you are going to have a VM installed.
The Stratagy DK does have full Automated Attendant functionality.
A couple of question first:
1. do you have a DKT 20 key handset to do the required system programming?
2. do you have the Stratagy DK VM admin software and null modem cable?
3. do you have a DK40 and Stratagy DK I&M manual?
The DK40's built in AA is actually the ACD function that requires a R key to activate it and then using a couple of SLT extns you could hook up a digital announcer to play queueing messages. This is not a AA like the Stratagy DK.
I would suggest you contact one of the guys on here and get someone to do it for you as you have said you are not familliar with the Toshiba product range.
Good luck