It would be difficult to find Electrolytic capacitors smaller then 100nF. Electrolytics are only used for bigger capacitances, becase their technology is not necessary for small capacitances and they have too many disadvantages for small values.
But apart from that, you are approaching your problem from the wrong direction.
1. Determine which capacitor you want to use.
2. Get a datasheet for it.
3. Find a footprint based on the size or name of the housing, and not on the capacitor value.
It is also very easy in KiCad to either make a new footprint, or to modify an existing one.