First, I don't recommend using the IIS_IUSRS account for this. I strongly recommend creating a service account to run your application under. Take a look at this:
Specify an Identity for an Application Pool (IIS 7)[
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Second, for your deployment, I suggest writing a PowerShell script. This script would create your Application Pool, set the identity of the pool, create the website or directory in IIS, and create the physical folder for the web site with appropriate permissions. This link will give you more guidance on doing it:
PowerShell Snap-in: Creating Web-Sites, Web applications, Virtual Directories and Application Pools [
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I hope this helps!