Neither would fry it unless they're a different pin count and you jam em in or something.
Check the chipset on the motherboard to make sure it can support the upgraded processor FSB. Dell's website should have the appropriate information, though I'd imagine those 3 procs would all run the same FSB. Even if the motherboard didn't support it, it would toast anything, it just would run slower, or possibly not at all.
Don't use the Celeron though, it'd actually run slower than the 2.4 P4