Re DTC 60/70, that is correct, definitely not good for street use and a lot of e46 folks mix the pad compounds as you described. Do not personally know of anyone using Ferodo.
If you do not want to swap pads for the track, then some sort of mixed compound like the Hawk HP+ or the Ferodo 2500 will have to be it. Based on the below data, it seems like the Ferodo has a similar bite to OEM but is capable of sustaining it at higher temperatures for less fade.
Here are two Mu vs Temperature charts that may help you make your decision (700*C = 1292*F):
