Kap,
it would help a to understand the intended function. Is this is a laptop that can play music when needed, or a machine being acquired for the purpose of playing music?
Decide on how much storage you feel you need on the machine itself. Its all good advice that was given above. The bottom line here is SSDs excel at speed because there are no moving parts. Program statups and some tasks are all done faster, which is great for running software like media players and sound manipulators and such, Their down side is their high cost and a lower reliability compared to HHDs. Storing music files themselves requires a lot of capacity and it does not need to be fast. So the cheaper, more reliable, spinning HDDs are preferred.
If you plan to stream to Bluetooth make sure the Laptop has a Bluetooth transmitter... don't laugh, not all do. Although you can use an external dongle xmitter if you need to.
Will you be connecting to a network? The internet? with a wired connection, a wireless connection, or both?
It used to be that not all HDMI equipped laptops allowed sound transfer through the HDMI port (they were intended only to support dual display). This may have changed over time. It may be more standard now.
What kind of optical disk drive will it need? You a disk guy? You gotta burn blue rays? Ya gotta read em? My preference is for an external optical drive, just because they seem less trouble prone than the ones inside of laptops. Probably due to the amount of movement and abuse my laptop likely sees. I actua;;y use a BRD burner made for a desktop and connect it via USB to the laptop. I process and rip all my music on my laptop, then store the completed files on a NAS.
Don't be afraid to do this in pieces. Laptop now, and music storage later when more funds are available. You can always use large thumb drives to store a small music collection in the beginning and the copy it over to a larger NAS or external drive later.
One idea I just found out about a few weeks ago was this: I replaced my home router with a Synology model. The new router has a USB port that you can attach an external drive to. In effect, it gives you a NAS without needing to buy a NAS box. You only need locate the external drive and the router in the same place.