I don't know how things work with the BetaMac system, but with a PC you would need to have a suitable receiver system which connects to your domestic WLAN and provides amplification etc for the speakers.
I recently bought the Philips MCi500H which combines CD, VHF-FM, a hard disk, a USB port and Internet radio - as well as an 'aux' input for another source (e.g. your TV). It connects to the Internet via my WLAN; although with Windows Media Player 11 I could 'stream' music files from my PC to the system, I don't actually bother as I prefer the vast range of Internet radio available.
You can 'rip' from CD to hard disk, record from VHF-FM or 'aux' to hard disk and then copy appropriate files to a USB stick.
You cannot 'burn' to CD - but most PCs will allow you to burn CDs with files imported from a USB stick.
The only thing which isn't possible is direct recording from Internet radio to hard disk. Although if you connect a PC to the 'aux' input, you can do it that way.
The Destruction Manual only refers to PCs, so I have no idea whether the Philips MCi500H is compatible with BetaMac, sorry.