if i put a gtx 670 superclocked in my dell inspirion (i5 processor) and changed the power supply to a 850 watt one, would that run well? or would the computer crash because there are other necessary components that i don't have?
http://www.dell.com/us/p/inspiron-620/pd
is there someway that the card could accidentally use too much power and go over the 600 psu? thats what im worried about.
if you haven't, i'd go ahead and upgrade to 8gb's of RAM, your processor is ok, and for the power supply, the max power it used in benchmarks is under 320w, those power supplies give you plenty of room, a quality 450w would be fine.
if you only plan to use one monitor (your monitor is 1080p or higher right?) then this will be great
g.skill is generally one of the cheapest and still best quality, corsair id good too, kingston is fine, i'd recommend getting one with a heatsink though, but any of these should be good