Since he's got a solid-state, you can cut back on the mass storage - a 1TB Caviar Blue will work just as well as the Black (a little slower, but it's mass storage; not a big deal).
Definitely cut back on the power supply - not only is the HX series expensive as it is, but 750W is more than enough for 3 vanilla 660s. If he's not planning on tossing another 660 in there, something like a Seasonic M12II 520W will do just fine. (Other quality modular options include the Rosewill Capstone 550M, PC Power & Cooling Silencer Mk.III 500W, and Seasonic G-Series SSR-550RM).