If you are using an image, you would need to create the image every time you wanted to deploy it to have the latest dat files. I would not recommend deploying the Agent with your image. You will have the same Agent GUID each time you used the image. Push the Agent out to the new machine using ePO. Believe me it will keep you from having issues later. This is what my PC Support config center did, until I talked them into, not deploying the agent with the image. Once you have installed the agent, send a wakeup call, to update the dats.
Hi af77, this is possible using the MID (McAfee Install Designer) so you can create a VirusScan package with a specific DAT file inluded
Of course of you are using an ePO environment then you'll need to delete the GUID registry key before imaging the computer so it will be recreated at the next boot as mrandolp told
or at the end of your deployment run a task/ script that runs the autoupdate- "c:\program files\mcafee\virusscan enterprise\mcupdate.exe" /update /quiet