Hey - some great information in this thread: Patch Manager - Can it be installed on the same server as other Orion modules?
Typically, customers would deploy Patch Manager on a separate server to Orion & just install the web console component of Patch Manager on the Orion server.
Hope that helps.
You can install them all on the same server, and ideally you would use an external SQL DB. I would also recommend just skipping the orion part of patch manager installation because its useless. Just my opinion here but just use the MMC console and forget the orion tab even exists.