im not sure about gigabytes warranties, but be sure you get a lifetime warranty on your video card.
evga offers a great warranty for these.
you can read this to help you pick out your power supply
to be honest, the next psu i buy will be made by pc power and cooling
also, you may be able to afford the i7 920 setup (budget 2k?), if you can, go with that instead
cpu intel i7 920
mobo, x58 board by biostar lga 1366 socket.
ddr3 tripple channel, 1333 is fine i think.
you will be pleased as this is the next generation of intel.
also, dont skimp out on the HD either, get one with 32mb cache. im using a 16mb cache, but i bought this over a year ago.
edit : let me add this in.
you can go a lil cheaper on the video card for now if you must, thats allways an easy upgrade.
your mobo is the hardest upgrade. this is why i say go for the i7 setup as it is a different chipset than that e8000 series.
you can allways just sell a video card and slap in a new one later.