First, make sure that your GCT has an IDE header soldered in place so that you can connect a hard drive.
If not then you cannot add a hard drive (someone on this board can solder one in for you $$$).
Otherwise you need to either put 98 Lite onto a compact flash card and
1) Use an external USB hard drive
OR
2)connect it to your mp3 server thru your home network (probably using a USB NIC)
If you already have the IDE header:
Get a laptop hard drive, buy the special twisted cable from Badflash, upgrade the RAM to 128, intsall Windows 98 or ME
remove the internal modem so you can fit the hard drive, Buy a mini-plug to RCA adapter for your stereo at Radio Shaq and you're all set.