you do not need a second radiator for your setup, the BIX II will be more than enough for handle your components. If you dont mind ordering from two stores i say get the d5 tdx combo from danger den for 108, but get the rest of the stuff from here
as they have better pricing on stuff like arctic silver, sunon fans, and they carry 7/16" ID 5/8" OD Tygon tubing which will work just as good as 1/2" but is easier to work with. You dont even need clamps as the fit is just perfect.
Concerning your GPU block, i know you like it but i still advise to change it. You dont want to bottleneck your flow with these 1/4" barbs. You are getting high end parts, but you are essentially ruining efficiency based on the gpu block. Even if you do keep the gpu block, run everything in a single loop, dont use any splitters or anything like that.