I doubt you will find a pump that exactly fits your flow requirements.
My suggestion is that you use the smallest pump that accomplishes the rise from pan to above ceiling. It will pump too much water, and could be damaged if you block the flow. What you need is a reservoir above ceiling that holds the water, with an overflow pipe back to the bottom. The pump, at the bottom, pumps water up to the drip pan through one hose or pipe. An overflow from the pan goes back down to the bottom reservoir with a larger (unpressurized) hose or pipe.
The rate of flow of the drip could be controlled by a needle valve, rather than pump rate.
And OH, by the way, since this IS posted on the Organic Gardening site, please make sure you use no pesticides or herbicides in this apparatus.