Script the installation of Patches

Hi Guys,

I need to update a bunch of ESXi5.5 Standalone Hosts, in approx. 160 remote locations.

As the Hosts are Standalone, vMotion, etc... aren't available options

I'm trying to create a script to do the following

1. Stage Updates ESXi55 from VUM
2. Power-Down all running VM's on each host (I have found how to do this by calling a list of VM's from a .csv and using the Stop-VM command on each VM)
3. Place the Host in Maintenance Mode
4. install the Patches / Updates
5. Reboot the Host once the installations of Patches/Updates is complete
6. Power-up the same VM's that were earlier shutdown (again, found this by using the Start-VM command in step 2 above)
7. Run a report on the Patching for Compliance checks (following a discussion by LucD for this)

Has anyone tried this from PowerCLI or, will I need to stick with the GUI ?

Any help on any piece above would be great.

Thanks