Go for it! Podfic, surprisingly fun. Yes, generally the Done Thing is to ask for permission from the author. I would really advise it and I can't imagine they say no often. But, yeah, if you're going to post it places, it seems nice to do, as an author.

If it's just for you, I can't see that it matters but then what's the fun?!

Hee! I too would prefer a lemur. They are the best, and would NEVER hate me.