A.
anwered by: isteinhoff
You would need these reducers, and then a traditional External Cup 1-1/8 Headset. So long as the fork you are putting on there has a Straight Steerer Tube (Likely on a 26in V 700), you'd be all good.
For headsets you can use, try the following in the description for a traditional External Headset: EC34/28.6 - EC34/30