Actually, if you're just wondering which one provides more power, they're either exactly the same, or the 465 provides more. I know for a fact that the 451 doesn't provide more wattage, and that the 465 is a newer model, so the 465 is your best bet.
The 465p-ve comes in two flavors, 465p-ve and 465p-ve(FC). The basic difference is that the FC version has "Fan Control," in which the second fan shuts down when the motherboard goes into sleep mode. Dunno if that matters to you, but there are other threads in this very board where I was asking about this model of power supply. I decided it didn't suit my needs, but it may very well suit yours.
