You can not order the hard drive form guitar center, but you can purchase the cd drive form them. Try compusa, bestbuy or even ebay!
CD Drive
http://www.sweetwater.com/store/detail/CDM25
Hard Drive
http://www.mpc-forums.com/viewtopic.php?t=52902
The following hard drives have been tested and approved for use in the MPC2500:
Seagate ST92011A ST92011A 20GB
Fujitsu MHN2200AT MHN2200AT 20GB
Fujitsu MHM2200AT MHM2200AT 20GB
Toshiba MK4026GAX MK4026GAX 40GB
Hitachi Travelstar HTS541080G9AT00 80GB
