If you want to oc, you need a good psu that supplies stable voltage.
a golden rule to remember about psu's are that you get what you pay for.
any psu under $50~60 is a bad one. so go toward $80~90 if you have enough money. personally, I'm not rich so i got a aspire 500 W for $50 but it is rock stable.
brand name is also important. If you had to choose between a 400W Forton and 550W Powmax, definitely go for Forton because that's a name brand. Btw, wattage over 400 is preferrable if you really want to oc.
Your CPU isn't all that bad. Ppl oc with Celeron, so not a big deal. But to get a good speed out of one of those, you'll need a good cooling. H2O if you're good at it(installing), air if not(good hsf needed)
About vid. card, 64 isn't that bad. lol, I use 32 that my friend gave me cuz I really do think that vid. cards are very expensive and unless you're into extreme gaming, 3D designing and stuff like that, you don't need that good of a vid. card. My aim right now is 128.
your ram is fine like everyone said.