Me too! Been itching to do a Dragonlance RP but I've GM'd a few RPs lately and they ended with me not being able to GM them anymore because it was too much work while I was way too busy.
But I agree with your idea, it's what I've been thinking too. The group will have to stick together as a whole, their ideals have to guide them to the same end no matter how different they may be. For example a dark-robed wizard might look to increase his power by claiming the power the group wants to destroy as his own, while the gallant knight has sworn to destroy this evil without any sort of reward whatsoever. No matter what end-game they seek, their paths may be different but they are working towards the same goal. The group has to split up sometimes in my opinion, it makes for a much more fun and creates more exciting situations. For example one part of the group is taken captive, the other part have to rescue them from Draconians or something else exciting!
The biggest challange of this RP is however to create a story that drives everyone forward consistantly. Then again, I'm not sure how many will join in.