Yeah I'd definatly go with evil's. I'm mostly curious as to how people are mounting it. I have a biocube open top with a MH fixture. I'm worried that it'll be obstructive.
Generally speaking you can put the PAR38 lamps in any fixture with that socket type. The way you put it on the tank is up to you. Many people use the rail lighting because it's stylish. I want to do something similar but I don't want it hanging from the ceiling.
You just gotta look around I guess. Only thing to be mindful of is to ensure that there is ventilation and not block the housing of the bulb.
i would pm clive (evilc) on nano-reefs. you cant use them in can track lighting i am gonna use them on my 40 breeder total of 5 for a japanese style reef