Ok, built a custom canopy for 3ea 250W MH lamps. Canopy is 5' long with 1ea 4' T5 rigs on each side. These two bulbs are for standalone coral fluorescence display....if it were you what 2 bulbs would you go with...
250 watt DE Bulbs where few back in the day, and with the leap in LED I think the selection may even be smaller. Aqualine,and Hamilton are the 2 I used when I had a DE set up.