PS3 is so overhyped its UNBELIEVABLE!!!
Companies such as ATI, Nvidia, Microsoft, AMD, Intel etc would lose so much money if there best products were less powerful then a £300 pound console.
As for the graphics card, your system is way underpowerd for a £200 graphics card. Upgrade your CPU to at least an entry level 64 and then go for a MSI 7800gt (£250), X850 XT PE (£200 from overclockers) or wait for the next gen ATi's (X1600).