Has anyone tried to dismantle Current Nova Extreme Pro 20" and cram it into the Biocube hood? It looks like it may fit. I believe the dimensions of just the end caps and reflector is around 18”x12”x2” (similar to http://www.aquarium-supply.biz/Current_USA...p/rcu01136.htm)

I know buying a new one of this costs about the same as going LEDs, but I can possible get a used one for $125.

I would get LEDs you will be able to keep much more corals than with that fixture. Plus you get the shimmer effect of Metal Halid but no heat transfer to the tank.