Thought I'd share this with any future Lighting DIY'ers out there.
Here's a shot of an 8x10x8 electrical box I rescued from a junk bin to house the ballasts for our lighting. So far it's working out great. Drill a few holes, a few mongo pop rivits later and viola. In there now are just two Advanced 71A3592 ballasts to drive the 250w Iwasaki's. We have a MAGNETEK 1030-93-500K ballast due in tommorrow to drive the 400w, there should be plenty of room to fit it into the top portion of the box.
So far it's working out well. Looks like I may need to add a fan to it to help keep things cool, with just the 250's in there it gets a tad bit warm since it's sealed up pretty tight (actually it was a watertight enclosure). Noise isn't too bad, a bit of vibration hum but I think it's more from resonating inside the box. I'll sort it out after I get the 400 in there.
All connections but those going to the lights (for now) are all soldered and covered with heat shrink tubing to help prevent and of the smoke from falling out.