Several folks have given you the best answer you'll get I think, and that is to pick out your wood in person. Walnut and Cherry can be wonderful to work with - each have their own pros and cons, and each piece of wood is different from the next. I've done some very detailed carving in cherry, and it isn't easy, but it's also not impossible either. As said, Cherry does tend to split/splinter easily for some reason. A really good piece of black walnut is a joy to work with, but a light punky piece you will curse. Maple is the same way, at Dixon's last summer I tried to buy a piece of sugar maple, and every piece I picked up (save for the $$$$$ pieces) was lighter and softer than the nice pieces of red maple. I've even used Norway maple and Sycamore maple, essentially weeds in New England! Find the densest piece of wood you can, then look for grain through the wrist and lock, and lastly look for figure.
-Eric