1: Get a wiring harness with a relay
2: my bias having tried various bulbs is to stick with good old boring halogen. Hella does make a 100W halogen which is off road use only......
A friend of mine runs a land rover / range rover specialty repair shop. Based on his experience, they are capable of stopping anywhere, anytime, at any cost.
I don't know about the brakes, only their unreliability.