Don't get that crap Logisys PSU. Get something like this instead:http://pcpartpicker.com/part/antec-power-supply-vp450
That Rosewill Green isn't too much better than the Logisys either.
Logisys makes garbage PSUs that shouldn't be trusted. Agreed with above on not getting the GTX 550 Ti, but I wouldn't get the 6870. The 7770 is extremely close to it in performance with current drivers (right on-par with it if you count some of the best 7770 models) and the 6870 is way to the 7850 1GB in price to be worth buying.