I wonder sometimes about how MUCH light you can get out of the 7 inch headlamps, and instead of adding a pair of spots or extra driving lamps,  you could just turn on both filaments (low &high) of the headlamps using a set of relays.

 

Could you just add a shunt to the wiring so both  filaments are powered when you hit the high beams?  I think you'd probably be at the limit of the wiring (65W + 55W= 120W or 10 amps each) plus an amp or two to make up for the old wires.

 

Then you'd get both the wider beam with the  longer high beams.

You would need to increase the gauge of the wiring throughout the circuit so you could increase the amperage of the fuses to prevent blowing the fuses on the inrush current. You would need better heat rejection, and you would probably burn out the filaments in the bulbs a lot faster. Auxiliary lights are a much better idea.