need advice for hooking up backup light

OK folks.. I just brought a PIAA 1500 model backup lights kit for my taco. I would like to know which way better in term of safety without burning your wires or fuse.
the first choice: follow kit set up to install them. ( got the wires/ fuse/ on-off switch.)

the second choice: slap the backup light on.. just splice the wires and add a fuse to protect the system to the taco backup wires. then call it a day.

the lights are 50 watts.. so I want to make sure it do it right.

 

Third choice.
Run a hot with fuse from the battery to a relay and take a leg from the back up lights to switch the relay.

 

That's the best choice...