Peter recently linked to this PATA/IDE SSD which would work fine in an empeg : http://www.amazon.co.uk/gp/product/B007IXORCO

Another route is to use CompactFlash cards, and a CF to IDE converter. Some converters even match the dimensions for the existing hard drives, making for a quick and easy mounting job.

For pure music, the empeg is still one of the best options. If you have a mix of podcasts, most people here have just gone down the route of playing those off a mobile device. The empeg could still be fitted, and use of the aux port would allow a mobile device to be used. If you want to get fancy, adding a Bluetooth A2DP receiver to the aux port would allow the mobile device to play wirelessly to the empeg AUX port.