I know I'm a little late to the game by posting on this threat, but you know how that goes. I am a huge fan of Pathfinder. What they did with the rogue class, giving them access to extra abilities every-other level really makes taking 20 levels desirable.
At any rate, if you haven't seen it yet, they released a lot of their content for free. http://www.d20pfsrd.com/
Also, they published a really neat book 'The Noble Wild', and gave stats / rules for integrating a talking animal PC with class levels into the world. I am currently playing a Black Panther Ranger / rogue with great success. Getting pounce is just <3. Their prestige classes are also very neat. I suggest looking into War Mount. It gives you a humanoid rider of a certain hd (or you can designate a party member, which I did), and gives them a lot of the benefits of the class you are taking.
Have a good one folks,