Looks awesome! I just got this tank and can't wait to set it up... need to build a stand for it but the weather has been bad here so I can't do all the sanding and staining I need to do yet.
I'd advise against putting killifish in it, they're very
good jumpers. I had mine in a covered 10 gallon tank with a divider in it, my betta in one half and my killifish in the other half. I had the water level about 2 inches below the top of the divider and there was only about 3/4 to 1 inch of space between the divider and the top of the tank and the male managed to jump over into the side with my betta. Thankfully I caught them before they killed each other.