Corsiar HX 520w enough?

I was looking to replace my old noisy tagan psu, i was advised on this forum that seasonic or corsair are good and quiet. I was going to buy the corsair HX series but which one 520w or 620w? My budget is tight but i would spend the extra for a bit of future proofing but if the HX 520w will last me a few years that will do. I currently own a 7800 gt card but plan on upgrading to 8800 gts from what I understand its no all about the wattage. I dont plan on sli but I many upgarde to quad core in the future or newer 45nm chips when they come out etc

My current system
E4300 @3Ghz
abit Quad GT
2g geil pc6400
7800 gt
2 x wd 320g

Thanks

plenty. good choice.

By far

Good choice,and recomended:)

Too much ;)

Perfect, as it'll give you room to expand without a hefty pricetag.

I'd always strech yourself as much as possible, if you have the cash for the 620w, get it, if not the 520w isn't a bad choice either simply because of the design putting most of the available wattage available on the 12v rail instead of bumping up the 5v rails that hardly need that amount of power.