First off, why are you going for the e2160? You are spending a lot of money and getting some pretty good equipment, yet you skimp on one of the most... erm, the most important part? Go for a Core 2 Duo with good overclock-ability. Sure the e2160 can be OC to 3.0GHz, but you can get the other Core 2 Duo's to go even faster than that.
You shouldn't need a sound card. The onboard sound is enough for all but the ones wanting to use their PC for a home theater system. Also, you should consider Vista Home Premium x64 instead. It has everything you will need and it is cheaper. Go with 4GB of RAM as anything more with your system would be overkill and you would not see much more improvement with any more RAM.
This is the only GTS they had on that site and it is very expensive:
Product Specification | Ascent Technology : New Zealand Computer Hardware, New Zealand Computer Software, New Zealand Online Shop, Wellington Computer Hardware, Wellington Computer Software, Wellington Online Shop
And here is the best cooler you will find:
Ultra-120 Extreme