In general, most red leafed JM's have greater sun tolerance than those with lighter colored foliage. Both 'Bloodgood' and 'Shaina' are often recommended for hot, sunny locations because of this feature. In climates with hot, sunny summers and drier conditions, I'd still recommend a siting that offers some protection from intense afternoon sun. These really are understory trees by nature and that type of location is pretty much ideal for any JM without having to make accommodations for extra watering or potential for leaf scorch while young.

I live a couple of hours east of you in Dickson, TN.

GardenGal is correct. These varieties are billed for 'full sun', but in our climate full sun is not the same as full sun in Seattle, let's say. Part of this is due to latitude. We are closer to the equator, and therefore the sun's rays strike us more directly. Couple that with killer humidity and you have a recipie for stress on a JM.

The most ideal situation would be to plant the trees in large pots and try them in different areas over a season or two to find the "perfect" location. If you can't do this, I would give Bloodgood the most sun and the 'dwarf Atropurpureum' (there is no such variety, by the way) the most shade, simply because we have no idea what it really is at this point. My Shaina gets about 5 hours of sun a day and seems to love it. She is semi-shaded in late afternoon - the most stressful part of the day for plants. One trick you might try is to plant a large Crepe Myrtle strategically so it will shade Shaina in the afternoon. They are tall -growing, beautiful, relatively inexpensive for a large plant, yet they don't create dense shade. Nor will Shaina ever get too big and look out of place near the Crepe Myrtle. The variety called "Watermelon" looks especially nice with a red-leaved plant beside it.