AMD usally do the same processors as intel but at a lower price. the pentium 4 should be cheaper than the AMD becuase it is 32-bit not 64-bit like the AMD processor. I would recommend the AMD one if the price is not too much more than the pentium but becuase the AMD is sort of new all programs work on it, but only a few programs ulitise the design of the chip.
microdirect sell it at £138 and an 'Intel Pentium® 4 3.2GHz' at £142.
Hope this helps