[Halcyon]

Anything around 400Watts and upwards should be fine for a Pentium4.

Depending on if you want to invest much money in this system, a Seasonic power supply is rock solid.
If you just need something to get you going again then any power supply above £25 should do.

If that is still too much a cheap as chips power supply can be bought for about £10 but the quality is not guarenteed to be much good.

Let's hope the supply didnt short your other components. If it was a newish computer with a decent power supply it should have had some protection circuits built in.