Re: aux. motor bracket
I'm not sure what you mean about notches. Nor what you mean about full tilt. If you mean you want to tilt the motor up when the bracket is raised up, I would advise against it. The bouncing you may encounter may pull the whole thing off the back of the boat, motor and all.
Kickers on brackets are intended to be kept in the down position at all times. Dangerous if you don't. In the up position, with the boat at rest, the motor should be out of the water. If its not, the bracket is mounted too low on the transom.
You are running a kicker here, not a main engine, and you aren't concerned about planing. Thus the cav plate's location is of little importance, just the position of the prop.
Modern OB brackets have about an 11" vertical travel. Like I said before, the old ones are pretty crappy. If yours won't travel that much, you may not be able to achieve a good compromise.