Without a sump, I would recomend setting the fuge higher than the display tank with a Hang-on-back type of overflow returning water to the display tank.
Use a powerhead in the display to supply the fuge. In case of power outage, the supply stops. The siphon from the fuge will halt, but still will be primed. When the power returns, the supply will begin filling the fuge to the overflow point and the siphon will resume.
If you do ith the other way ( powerhead in fuge, overflow on display) in the above mentioned power outage, The return will stop before the siphon is halted. The water level in the display tank will continue to feed the fuge until it reaches an equilibrium with the over flow. Without a sump, That means water on the floor. When the power returns, the powerhead pumps the fuge out to the tank.
Ideally, drilling and baffeling the tank would be the most attractive. Unfortunately, 10g tanks are made of tempered glass and thus is nearly impossible.
I personally have a total gravity system (no powerhead) of which I am very fond.