I'd go wth the XFX Pro that is made by Seasonic. The VP550P is made by Delta Electronics is also a good PSU but I would want all of the cables sleeved. The OCZ imade by Sirtec is also good. All are well reviewed by reputable PSU review sites.
XFX Review: http://www.kitguru.net/components/power-supplies/zardon/xfx-pro-series-450w-and-550w-power-supply-review/8/
OCZ Review: http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story4&reid=248
VP550P Review: http://www.techpowerup.com/reviews/Antec/VP550P/
I wouldn't have an issue buying any of those three PSUs....choose whichever one is the least expensive.