Help with pairing the right headset to a new 3T fork I recently purchased an Aventon Mataro (http://aventonbikes.com/track/) frame and a 3T Funda Pro with tapered fork (1 1/4' - 1 1/8' 1.25 ). I've been trying to figure out which headset I need to fit the fork to my frame. I am still fairly new, and looking at Cane Creek's page of all the headsets is confusing me even more. Can someone point me in the right direction or tell me what I need to look for in the specs?
Measure the inner diameter of the headtube, both upper and lower. These are the key measures in combination with the fork dimensions. You probably want to confirm that the angle of the inner chamfer angles are 45 degrees (and not 36) as well.

Once you have those measurements you can start searching. Note that it says "integrated" (= IS) on the Aventon page, which is also a key. It seems to me that there is a risk that you can not fit a tapered fork straightforwardly into your steering tube though, but Cane Creek can probably help you out there. However, that depends entirely on the measures you obtain.