May I suggest a relay and wiring the lights through a switch and your dimmer.

Works great.  Turn on your switch.  Drive around with your low beams.  Hit the brights and your KC Highlights or (my Cibie Oscars) come on.  Turn off the switch and you still have your low beams and brights.

Fairly simple to wire.  Need some #12, a relay, a switch, solderless crimps, 12 volt tester, electricians tape, zip ties  done!