Hickory is easy to overdue, I think. Cheddar would be my only choice for hickory. Stay far away from mesquite in my opinion. You might be on the right track with fruit woods. Apple and cherry are easy enough to come by commercially. I have heard the wood from a Bradford Pear is nearly the same as a regular pear fruit tree. Those trees are a dime a dozen when broken by ice or wind. I haven't tried it yet though.