I tried looking around these forums and Google for the answer, and I believe the answer is likely obvious which is why it isn't found. I did want to verify this before wiping my current installation though. If I already set up my server manually, can I replace it with Virtualmin? I followed the guides available on Linode.com to get everything up and running.
I also wanted to ask if there's a billing system software that would plugin to the store's front-end/usermin end to process payments while I was here, but if that's a bit out of scope for this forum I understand.
Thanks for any help, I really look forward to streamlining my domain creation process with Virtualmin!
Installing Virtualmin over the top of an existing webserver is generally not recommended. Virtualmin is a heck of a lot more than an interface to your webserver, so it is best to start with a clean, minimal install of your operating system. One of the first things the installer does is uninstall any related services before installing them and configuring things to suit. This would generally mess up your existing config. If you are a reasonably skilled sysadmin, you can probably fix things, but again, that process has no support from anyone.
I don't use a billing system myself, but I understand Clientexec and WHMCS both work with Virtualmin.