I use stackers. I have KW, Carnahan's (now West Coast Cages), and was lucky enough to find a old Glick (an antique you might say but much sturdier than the best cage companies today put out). I love the cages I have.
I keep my stackers, metal cans of feed and bedding, bales of hay for goats (and a bit for the rabbits), in my 12x32 mini-barn. Here is a pic of my barn. It has three small windows, double-dutch doors on one side, a garage door on one end, and a ridge vent that goes the length of the roof. It also has a small loft. It was placed to allow the best breeze to go through one door and out the other. I attached pvc pipe misters above the garage door to cool the air that goes into the barn in summer. I also use a portable livestock fan to help pull the air through on hot days w/no breeze. The misters and fan help lower the inside temp 10 - 15 degrees. This year I might add another vent and grow sunflowers on the sides that get afternoon sun in hope of being able to lower the temp even more. In winter, I can close up the barn on nights it gets below freezing.
Here are some pics of it the day it arrived.
Side w/two windows and double dutch doors
Looking in through the garage door. Loft is at the opposite end.
Looking out the dutch doors.
On a side note, my favorite set up is hanging cages in a barn w/dirt floor and good ventilation.