Also, correct me if I'm wrong, (which i'm not) but from that list you've only bought the waterblock to go over the cpu. That will be about as effective as blowing on it tbh. You know you need a pump, special water (de ionised or something that will prevent rust) in addition to experience in PC building. You don't get a watercooling system for $15, so given that your current cooling system is physically unworkable, just buy a cpu heatsink and fan.
Watercooling is required only for people who want a near silent PC, eg people who leave it on all night in the room they sleep in, or overclockers. Given that you are neither of these, the expense of watercooling (which actually costs upwards of $100 for even the most basic kit) is ludicrous!
On your website, the cheapest is:
http://www.newegg.com/app/ViewProductDe ... 060&depa=0
Also, if you want to build the PC for gamers, I would suggest getting a radeon 9800 or at least a 9700, yes.
Also, your monitor is an LCD, which is poor for gaming - they have a slow response time which can lead to a blurring effect on the screen. AND they are expensive. AVOID. Buy a cheaper normal monitor, and you might have enough money to buy a big 21' screen or something. But DON'T buy the LCD one.