If you can find an early Fizz, you can begin to put your team together. At level 7, you can add in Viktor for Battlecast and Sorcerer. Later, you should replace Cassiopeia with Soraka.
Additional comp tips
Mech items are very flexible as you can run dodge with Shroud, run Bramble, or even run crit with Infinity Edge. What we have is our general recommended setup.
Position Shaco on sides where you believe enemy carries will be. Also try to position the Mech where the enemy is most clumped so you can deal more splash damage and remember to avoid Zephyr if you don't have Quicksilver.