psu for my dell

hi guys,
iwant to buy a new psu for my dell inspiron 580s pc,since none of the good gpu work on the current stock psu.i also want to overclock the pc to atleast 4.0GHz aswell.
can u guys suggest any good psu which will fit inside,cuz my pc is really slim and quite tall.i will atleast need a 450w or 500w psu minimum.

thanx guys!

What will you be using the computer for? Are you planning on putting in a video card? Are you planning on upgrading the rest of the hardware?

Buy an antec 300 and a good psu. Slim pc's are never the way to go...

i'll mainly use it for gaming and some programming aswell.but most of the times i just use it for gaming.

Most (95%) of all Dells don't allow overclocking in the bios.

And you'll have to replace the CPU cooler if you can even overclock it, which I doubt.