Before experimenting with different wood, I'd highly recommend doing research into wood toxicity. I said it before in another thread from awhile ago
found here, and I'll say it again; it can be very dangerous for people with severe allergies to specific plants to ingest the wood from those plants.
It can also be hard to determine whether you are allergic or not until you get exposed. And at that point, there could be some serious reactions. Try sanding a bit of whatever you end up wanting to use, and rub it on a small patch of skin. If you have a reaction, don't use the wood. The only issue is that even if you aren't allergic, those who you share the mead with may well be.
This website has some good info about commonly toxic wood and would be a good starting place, IMO. There is also a PDF in that first link I posted with some good info on toxicity, though it is a bit less user friendly to read.
On a final note, we've used oak for so long because it is easy to work with, holds liquid well, is low in toxic tannins, and adds a nice flavor to its contents. Why mess with success?
Hope that helps!
Edit: Sorry if I sound super preachy about this subject. As an amateur woodworker, I am super anal about wood safety. The scariest part of wood allergies is that they are typically unknown to those who have them until a serious reaction occurs. And then, they become sensitized to that allergy, making it even worse if exposure happens again. People have died from it, and I'd like to make sure no one here on the forums falls into that category. Granted, most problems arise from inhaling the sawdust, but I'm sure soaking in alcohol would extract plenty of tannins to be an issue.