Fire starter should be a Red panda.
Should have an amazingly long tail by the time it gets done evolving. Should be a top of the line annoyer with some great offensive options and moderate access to grass moves. I wouldn't hesitate to call it a Glass Annoyer, like Sceptile. At the moment, Ninetails is the only fire annoyer, and a rather piss poor one at that. Should have a very high speed stat, high attack, and its move pool must have willowwisp, substitute, slack off, toxic, and a great deal of other annoyer tricks as well as an option to fireblitz. Drain Punch and Focus Punch would also be a great addition to its move pool. Its ability would have something to do with blinding the opponent when he comes into play, lowering their accuracy.
I support the squid as well, though how would we avoid a tenacrule rip off?
Someone mentioned a seal I believe. Other than a select few, Water has taken the defensive rout. The seal pokemon could give us a chance to change this. We give it the ability to cause a continuous rainstorm, already making it an ideal counter to most Sandstorm and Hail teams. It should have a monstrous speed stat, and a very high special attack. Essentially, this is the special version of Gyardoes. However, in order to keep it from obtaining that title, we should also give it the option to baton pass, and along with Vaporeon, this essentially makes a second type of Rainstorm team, where half ot the team is also designed to be a baton passer. Of course, you wouldn't have to pass to a water pokemon to get the full effect. Passing to a pokemon that has a fire weakness would also benefit greatly, or a pokemon that knows Thunder or has access to water moves.
As for Grass, try out a panther. No ideas for how it would play yet though.