I'm about to change my old 9800gt GPU for a better card...I was thinking of GTS 250 green because it was the strongest card that doesnt have any supplementary cables...im scared of getting cards with supplementary cables coz they tend to get burn because of my PSU..(it sucks 500w only) so..should i get the GTS 250?? or buy a new PSU (what brand and how many watts) and get a better card (lets say ATi 4890).should i play safe and get it?? or risk and spend more?? please do help..