This is a difficult planet due to that orientation toward the sun. If you have Fractal Terrains it should do this much easier but I'll let one of those guys answer that for sure. If you don't have that then I'd recommend doing it as a rectangle where the width is twice the height; this way you can lay out your bands properly. When you get something that you halfway like, then import it into Google Earth to see if things line up properly (make sure that there is no seam) and also check the bloat that happens in the middle and the pinch that happens at the poles. You will probably have to readjust the bands at that point (make the stuff at the poles extend further into the middle).
There is a mini tut by Jezelf in this thread for how to import an image into Google Earth (it starts at post #13).
Mixing hand drawn and randomly generated elements?