If you are looking for a low cost and reliable 600w grow light, you should try this Eurolux 600w grow light kit supplied from Maxibright.
The reflector supplied is a Euro reflector, which has a four metre cable to connect to your ballast and also holes for you to hang it easily.
The HID lamp supplied with this 600w grow light kit is a Eurolux 600w dual spectrum lamp, which is a red spectrum bulb with added blue to allow you to use it for both the vegetative stage and also the flowering stage.
The Eurolux ballast is very similar to a Maxibright Compact ballast, as all the components are resin encapsulated inside to prolong their lifespan, but this does make the ballast run slightly warmer than most other standard core coil ballasts, but if it is placed outside of your grow room or grow tent, it wont cause any extra heat problems inside.
All in all for the money this 600w grow light is hard to beat, as most of the cheaper 600w grow lights we have seen available, dont seem to get very good comments on the internet.