If you're not ready to "roll-yer-own" with regard to a relay harness, we also have one similar to what garberz posted, but with longer wires and less cost. Just does not have the jumper BroncoKelley mentioned for keeping both filaments lit at the same time.
Most people don't need that feature, but it is nice in the wilderness when you really want it all.
Not sure why his blew so quickly (obviously the heat was too much for it) when most others do not have that issue with the larger lights our Broncos have. This would be a very common issue with smaller lights, as they can't dissipate the heat as quickly. But I would guess it happens now and then no matter what you run.
Good luck.
Oh, the other theoretical solution to your issue is simply replacing the main headlight switch. However, this is only a long-term fix if your wiring is in perfect shape still and everything else is in good shape. Otherwise, it's likely just another temporary or very short-term fix until the circuit-breaker is overloaded again.
The relay kits take most of the load off of the main headlight switch and put it where it can be handled and do the most good.
paul