How to select a hard drive.

I need to replace the hard drive in a Dimension 8100. Dell does not offer a replacement. How do I know what is compatible other that the type of hookup it uses? Would this work? http://www.officedepot.com/ddSKU.do?level=SK&id=406166&Ntt=hard%20dive&Nty=1&Ntx=mode%20matchallpartial&Nr=100000&N=132433%204294963702&uniqueSearchFlag=true&Ntk=all&Ne=1%20105&An=text

We have lost our IT person and have a new employee starting soon. I am responsible for getting this computer running again.