Does anyone know if you can get these already inside a heatsink with fan? or do you pretty much have to build it yourself.? Do they get very hot. Do they even need the heatsink?
I have never seen IC ballasts sold with a heatsink or fan. I have read on another forum that the ballast can simply be placed on any piece of metal, and that is a sufficient heat sink. Most of the time they don't even need that though, depends on where you put it. If you want an easier solution, check this out, http://www.premiumaquatics.com/Merchant ... Ice-halide
This box will act as a heat sink, has all the connections, and you could easily cut a hole and install a cheap fan. HTH
The ballasts get pretty warm, but not blazing hot. I have mine mounted on a sheet of aluminum, which dissipates the heat sufficiently. You can also buy the IceCap 660 heatsink, which can be used with the MH ballasts. Here is a link to the part at OceanEncounter.
I have a 175 icecap ballast and it is almost colc to the touch when it is running. I highly doubt that a 250 would need a heatsink. I have mine placed on a shelf near the tank.