Deploy 3rd party Apps via Microsoft Deployment ToolKit
Solution 1:
If you add Office to the original image there is nothing that stops you from adding more applications the same time. Applications that supports unattended install (such as office) can be added as an optional application in MDT though, which makes it possible to select during installation. Personally I prefer to install 3rd party applications through GPO though, since that makes it simple to upgrade existing computers without wiping them (which pretty much MDT requires). Of course, if you have SCCM (System Center Configuration Manager), that gives you a much better management experience! With 30+ computers to manage I would consider installing that!