Ben,
To clarify further, 1 1/8" is the outside diameter of the steerer tube of the fork that you must buy separately to go with this frame. Contact On-One if you need a suggestion. 34mm is the standard outside diameter of the headset cups to be pressed into your frame. The head tube on your frame will actually be a tad tighter than that for a snug fit.
The Ritchey V2 in your link should fit just fine, the WCS will not.
These sites explain with pictures your other technical questions....
http://www.canecreek.com/manuals/Hea...ationGuide.pdf
http://www.parktool.com/blog/repair-...dset-standards