What you need to acheive your goal is the Microsoft Deployment Toolkit - MDT. MDT can be used in conjunction with WDS, and can make many things easier with a task based process. You load your drivers into the MDT driver store, and during image deployment, MDT will use PnP calls to install the proper drivers from the driver store, or you can group your drivers and use selection profiles to make sure that only the proper drivers are used. For boot images, you can create a selection profile for just network storage drivers. When new hardware arrives, you just import the drivers to the driver store and regenerate your boot images and them import them into WDS. More information on deployments can be on the Deploy and Deliver page of the Springboard Series on TechNet.
Hope this Helps,
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David
Windows Outreach Team - IT Pro