Try using a separate relay for the spot lights, and use the headlight relay to switch it. So it works the same but halves the draw. Use a 20 amp fuse for spot light relay.
200w divided by 12volts = 16amps.
Any creamy colour oil on your dipstick yet?
Start the car with radiator cap off if you get bubbles streaming (constant flow) out radiator you have problem. Give it a rev see if coolant shoots out. These will only happen if the headgasket is bad. If it doesn't happen still don't rule out a gasket!