A moby is going to be really hot. If you like the wrap (I prefer wraps for newborns), there are cooler fabrics to choose from. Wrapsody has one, and there are also gauze wraps. Another option is a ring sling. Linen would be my preference, although if you want a water rs, mesh or solarveil are also options.
I do not like the seven sling...there have been too many reports of poor quality for me to want to spend money on one.