If you can't find cherry, look for some apple. It too tends to be a lighter taste.
The bird will probably get PLENTY of smoke - I'm not a huge mesquite fan anyway, and thus don't even get near the smoker with it. I would stick with fruit woods and let the bird smoke with that the full time.
Cherry, Apple, Pear, Persimmon, Peach, Plum, etc. Most fruit woods will work pretty well.