Get the 7870 tahiti le either the power color 7870 myst or the sapphire 7870 XT. Better cards for the money, both outperforms the standard 7870. Get the plextor m5s, here's the list : http://pcpartpicker.com/p/D07R
Get the 7870 XT
You don't need 620w though. A 500w would be good enough.
The plextor m5s is cheaper, 40$ less, it's a good ssd, the samsung 840 pro is better, but you won't notice the difference, the plextor is one the best 128GB ssd price/performance, and it's reliable as well.