Smallest kit you'll probably find other than cocktail size would be a small jazz kit like gretsch
's Catalina Club Jazz Shell Kit
Specifications: 8 x 12-inch Mounted Tom, 14 x 14-inch Floor Tom, 14 x 18-inch Bass Drum
5 x 14-inch 8-Lug Snare Drum, Single Tom Holder.
The 14X18 in. bass will make the kits footprint fairly small compared to a standard or fusion size kit.