It's all about the yeast. You want to make sure that your yeast can stay happy in whatever temperatures you can maintain.
If your stout wants an Irish ale yeast, keep in mind that this yeast won't be happy with temperatures above 68 degrees F. Consider instead brewing a farmhouse ale. Some of these yeast strains can survive (and thrive!) at temperatures up to 90 degrees F.
As for storing your brew, pick the darkest, coolest corner you can find and put your brew there. Block all light. Crank up the AC.