How about drip irrigation?? You can hook the mainline tubing into a bucket, with a standard hydro-bucket fitting turn off valve. Have the mainlines snaked around, with few drip emiters inside each pot. Gravity feed will provide sufficient pressure... just go with higher GPM emmitters to compensate for the lower pressure... or no emmitters at all, just a length of 1/4" drip tubing with no emitter.
Or you could fit a garden hose onto the bucket, and use the SMALLER Dramm water breaker, the slim sized low pressure 170 model. Gravity should provide enough pressure to get your watering done.