Fair enough
3 - And it's overpriced for what you get. Although the monitoring is unmatched.
2 - That's as external as you can get

1 - Yes. No one company makes all the best parts.
But it did you no harm to look at it
Edit : I should say I'm not ignoring the questions you asked in your almost initial post. I simply don't know anything about 1/2 fittings.
As for the res, I'd get one if it fits, from anything I've read people seem to go for T lines when a res is not desirable due to space.
Unless you really want to go for the highest possible graphics clock then go for a non restrictive full cover block. Used to be a better idea to go for just a GPU block and ramsinks, but when the G80 arrived it was a better idea to go for full coverage to get the VRMs since the cards use silly amounts of power. At the time I do remember (was it Swiftech?) coming up with the idea of a passive coverall for each card, but keeping with a GPU block. That to me seemed like a good compromise, but I've heard nothing about it - not that I've looked - so it may not have taken off.
You are of course on the money for the CPU block. It's by almost all accounts the best performing.
I'm not so sure on 1/2 inch tubing, that's rather large bore. It has no negative effect, but it might make things tight internally.
I've tried Swiftech additive twice for about a year each. My current water has AquaComputer additive. I'm inclined to say the AquaComputer is the best. Although it equally could be the distilled water I got from (Homebase?) was not as clean as the distilled water I got from Halfords

None of them have produced a huge amount of gunk. The AquaComputer has produced nil though.
As for your questions on "will it fit" and if a double or triple rad is needed... something is ringing a bell, if you bear with me I'm going to have a look at something I read a while ago, if I can find it. Specifically a template which can be printed (?) and thermal capacity of radiators. Until I find them again though I won't be entirely convinced I read them in the first place
