Well personally i wouldn't worry about the 1/4" gap, but i think some 28 quarts might fit in your rack perfectly. I took some quick pictures of my rack to show you the large gaps i have and the tubs i use. I have just enough space to put the lids on for when they shed, makes them shed very quick and easily. Also the jump in humidity really gets them in the mood to get the old skin off.

PS: Yes the snakeless rack space is being used for clothes, but i might as well use it for something right!!