First thing you need, is to put the pump AFTER the reservoir, not in front of it. The pump needs to TAKE FROM the reservoir, and pump to the CPU, Vid card, then to the hard drives. I dont think having the second radiator is necessary. Just the one before the tank(reservoir) is needed. You need the tank to be unpressurized so you can add water to the system if needed.
Dont use 1/2 tubing unless its free and you are willing to do about half again the amount of work that you would with smaller tubing. 3/8ths is generally preferred. I think 1/2 much too expensive for the amount of cooling you will be doing, and you will run into turning radius problems with 1/2 that you WONT if you use 1/4 or 3/8.
Check out Google results :
http://directory.google.com/Top/Comp...rcooling/?tc=1
HardOCP:
http://www.hardocp.com/article.html?art=Mzkz
Overclockers(article about aquajoe):
http://www.overclockers.com/articles850/
KIT(for ideas, dont buy unless you believe it will do the job):
http://www.aquajoe.com/
Xoxide sales of watercooling cases/kits:
http://www.xoxide.com/watcoolcas1.html
Look and compare then decide what you want to do.