Get the switch that LJ3000 pointed you at. I've got one running my hazard lights, works fine and is weatherproof. You'll still need the relay that comes with the lights as any switch capable of safely handling the light's current is going to be way too big for the console.
If you want an LED in the other hole as an indicator you'll also need a "current limiting resistor" so it doesn't blow the first time you use it. YOu can get little black "clips" to hold the LED in place. You could possibly replace the provided switch with an illuminated one, but I don't know of any that are weatherproof.
You'll also want to find some sort of weatherproof connector for the wire run to the console so you can disconnect the switch to remove the console when you're taking off your tank. It only needs to be a 2 pin connector, any half decent auto parts shop should be able to sell you something appropriate, or you could just use male & female spade lugs and just attach them backwards to one of the wires so you can't connect the wires the wrong way round.
