I need a new power supply for a better videocard but what power supply do I need? I am clueless and searched on the net but don't know what I need to look for...

So I need help with this.
these are my power supply specs
Power Supply specs:
DC output Curent : +3.3V +5V +12V -5V -12V +5Vsb
10/5A 28.0A 34.0A 21.0A 0.5A 0.8A 2.0A
Total output Wattage: 450W
p.s. I have a PciE 1.0 motherboard so I'm looking for a 8800Gt of something in that range.