Convert-WindowsImage.ps1 is a very popular method to create VHD's with. However it's not a module, and in it's current form cant be added to one.
So I have started a new project on GitHub called WindowsImageTools and posted the results to the PowerShell Gallery.
It has a few functions so far. Convert-Wim2Vhd, to do the work, and New-UnattendXml because it hate having to edit XML to make minor changes. The resulting XML is universal in that it works on both 32 and 64 bit and will do a silent install (currently on Volume Media only). Then it auto-logs on the Admin and run a PowerShell script to kick off what ever you need bootstrapped (like DSC)