Well, cost saving can be a good and bad thing. Sometimes you really want quality, and have to pay accordingly.
Good example is the case/psu combo. Bad idea. Almost all power supplies that come with cases are terrible, and powerup is substandard at the best of times. In any case, 450 watts is not enough to power a GTX280, and a 600 isn't either. You need a minimum of a 750 watt quality psu. Bang for the buck there is the Corsair 750TX, though the 850 would be better. I run the 850TX with my GTX285, which uses less power than the 280.
750TX -
http://www.newegg.com/Product/Produc...9006&Tpk=750tx
The case itself is unlikely to be very good, 40 bucks in combo with a psu sure does send me a clear message. Think about something like the Antec 300, fine case that's relatively inexpensive.
http://www.newegg.com/Product/Produc...82E16811129042
You've chosen a 4GB kit for ram. It may or may not be compatible, a link might help in that regard, but OCZ doesn't list the motherboard in their configurator. Ram for the i7 is usually a 3 module kit for triple channel. Something along the lines of this corsair.
http://www.newegg.com/Product/Produc...82E16820145236
That's two corsair products in a row, accidental since I don't use their ram, but it is very good too.
Fans - may not need to purchase any of those, cases come with varying amounts and sizes of fans installed.
The motherboard is also one of those things that may or may not be fine. Personally, I prefer Asus boards. And if I don't use that, then it's Gigabyte.