Unless I am mistaken, any 2.5" drive will work in your system. The big thing to keep in mind is ensuring you are purchasing one for the interface you have (PATA vs SATA). Obviously, this is a major thing to remember.
But… any 2.5" should work within your system. And because you are replacing the one that you have already installed, there should be no requirement for a bracket. I don't believe the drives are using brackets anyways, but in case your system has it, just use what is on the old drive.
Last but not least. If you are unsure about something - definitely call up tech support. They are very helpful in providing details that you may need, or to guide you in a specific direction when it comes to the new drive. Plus - you can always make sure you validate that you aren't killing the warranty.
Hope this helps!