I'm not sure either, But you get to pick the color so it doesn't really matter. :p
On a side note, that tubing is supposed to be strong and hard to bend as I understand it. So you might need to use some of those 90 degree angle pieces. I see that as a positive though in some cases, although having 90 degree angle bends might affect your flow rating?? Unless the pieces are curved in the inside and only look square on the outside. Bah, who knows! Whatever you do it will end up looking great, everything else has so far!
The guy who owns the website also mentioned something about combining clear and webbed tubing for an awesome look. Something to think about at least.
About your graphic cards. Isn't there a way to paint them? I thought I heard something about being able to paint that kind of stuff awhile back? Anyways, they look fine, it's just a bit too... um... Christmas orientated looking. But hey! It IS December right!? :p
-SnowFire