So I am very new to water cooling, and decided to go with this XSPC water cooling kit (http://www.frozencpu.com/products/21235/ex-wat-270/XSPC...)
I saw that these have the barbed fittings, and hose clamps, and they aren't very attractive or seemingly as safe as threaded/compression fittings. Can someone recommend me a set of fairly priced compression fittings of the right size for this kit?
Barbs are perfectly safe; I only used barbs for 10+ years of watercooling. You just have to be careful and make sure you give yourself enough tubing, but that's the same concern with compression fittings, as well. Barbs can be very clean looking if you use larger barbs than tubing size (1/2" ID barbs, 7/16" ID tubing) as it makes a very tight fit and may not need clamps at all for a flush look. I'd really only recommend this for someone that has had a loop installed so they know what to expect...not necessarily a first time thing.
To answer your questions, those fittings and tubing would work...both are 7/16 ID & 5/8 OD.