I find Japanese maples to be pretty tough, and most of them prefer some shade, although I have some in full sun which are thriving. I think most are also hardy to zone 5, although they do prefer soil on the acidic side. My sister was pleasantly surprised to nurse a couple rather sickly and small Japanese maples in her zone 4 or 5 alkaline yard, both doing quite well after a couple seasons of TLC. We have a cousin who collects Japanese maples, and he regularly passes on his scratch-n-dents to us -- all but a small handful have been successfully rescued. I'd go to a reputable nursery in your area, which should carry trees that will thrive for you. Good luck, they are quite lovely trees - so many different colors and forms to choose from.
