Hi little x, noticed you're in TO too!
I agree with the others, unfortunately a 5g tank is really too small for any clown -- a single juvi might be okay for a while, but none are going to work long-term. A clown goby or trimma goby, or a small prawn goby with a pistol shrimp might be a better choice. Personally I'd leave the tank fishless, maybe keep a few sexy shrimp or a pair of harlequins (if you're willing/able to get starfish for them to eat) instead of a fish.