To be honest with you, a 430 watt power supply doesn't seem that smart to me. As someone said earlier, you want at least 40 amps on the +12 volt rail, that alone is over 400 watts... Do not, I repeat do NOT skimp out on your power supply. I'd get a powersupply that has 40amps on the 12 volt rail.
Also, when buying a PSU consider this... if you buy something that will operate at close to its maximum capacity, its life will be shortened. If you can afford to buy something that will operate at 55-70%, you'd be a lot safer, and prolongue the life of your PSU.
1) That processor isn't as good as the i5
2) You only have 1 stick of RAM so you're not taking advantage of dual channel memory.
3) The memory you've chosen isn't as fast
4) Yes the 7950 is better, but not by much. The 7870 XT is based on the 7950 architecture, if you overclock the 7870 XT it will perform the same as a stock 7950 for $80 less.