Missy, I don't think they're too picky as long as the soil is well draining. What some of mine are in right now is about equal parts perlite, peat moss, & vermiculite (which is actually the same mix I use for my indoor African violets). A few others are in about equal parts "regular" potting soil & perlite. I'm not too particular when repotting, other than making sure the soil drains really well. Of course, your mileage may vary.
I do know from my reading that there are others here on the adenium forum that can give you much more expert advice.
Mine are all outdoors in about 50% to 75% sun.
