Just about any Dell Mini Tower, or Mid Tower that can run that CPU can run an aftermarket PSU. The only exception that I can think of would be some workstations, and XPS models that use FBDIMM memory, or dual CPUs. Then you get into proprietary connectors. The Dell PSU wiring problem was over by the time 1333 fsb CPUs showed up.
desktops, SFF, and USFF have proprietary PSUs and the dell part is probably as good as it gets.
A model number and type of case would be helpful. They did make an awful lot of different computers. Some more different than others.