Which processors are compatible with motherboard dell model 0FH884 Intel i945p / pl / g / gz chipset?
Only Dell can provide that information.
You must ask Dell what processors are supported by THEIR BIOS.
Then, you can select from those processors.
A processor must be socket, BIOS, and chipset compatible.
Now, for such an old chipset, I question the value of trying to keep this system alive.