I figure I'll need good ceiling mounted bluetooth speakers and a bluetooth range extender on my PC in order to do this and get it working with Hubitat hub... Or is hubitat hub alone good enough to get this job done?
Im fairly sure that most users here are anti-bluetooth home automation.
Youll get good help for solutions around here for
Chromecast/ Google Home speaker groups (this is what i use)
or some network AVR audio receiver where you wire speakers in zones and control that through hubitat doing some sort of cloud or API call over your network. Denon, Yamaha, Sony come to mind here.
There is also squeezebox (logitech media server) integration.
Is the logitech media server a way I can make my hubitat speak a greeting message when I get home?
Sure, but it is a media server. It serves media to a player. So you need a player that is hooked up to the logitech media server. This device was typically a "squeezebox", when you bought the squeezebox you got the media server for free. There are some other workarounds involving computers if you don't want or have a squeezebox, but it is a simple integration if you have one.
There are many issues with Bluetooth that make it not the best choice for home automation. Range, lack of devices, and many other limitations.
I am far from a music snob, and I don't even have a stereo system set up right now, so take this for what it is worth. But Bluetooth is probably one of the worst choices for music in my opinion. Low bandwidth, tinny, flat music is what you will get from something like this. And I can't imagine the echo you will get from the various timings of getting a signal to these devices if you try to play in multiple rooms at once.
If you are going to the trouble to do whole home audio, you probably want something a little better than Bluetooth. I don't have a suggestion for you for devices though.
I think you'll be happier with the sound quality from anything else other than Bluetooth.
Some options to consider:
Amazon Echo - Can stream in every room
Google Home - Can stream in every room and you can cast to it from a device as well.
Apple HomePod - Can stream in every room and it supports AirPlay from a device.
Sonos - For ceiling mount speakers this is a good choice but the most expensive. You can stream in every room and it supports Apple AirPlay, but it also supports music stored on local Network Attached Storage (this is how I use mine for my personal music).
This is a bit of a hack but for the price but I just took apart Google Minis and ran a speaker wire to a real enclosed speaker; 2 can be paired as stereo. The build in chip has way more Ommmph that I would have thought. Powers a 6*9 very nicely. If you have a high level input on an amp (mostly car audio or after-market device) you can drive a proper distributed sound system.