instead of hortilux how about;
AgroMax 600 watt HPS Bulb
This bulb is perfect for people using 600 watt High Pressure Sodium systems. It offers an extremely high output of 95,000 lumens. Standard 600w HPS bulbs only emit 80,000 lumens. Its spectrum is also made specifically for plant growth with an additional 30% more "blue" spectrum over standard HPS bulbs. More "blue" spectrum means the bulb has a more complete light spectrum equating into better/more plant growth. This is a specialty horticultural bulb designed and manufactured for plant growth!
OR
SunMaster 600w HPS Bulb
This is a premium SUNMASTER Brand high output spectrally enhanced horticultural bulb. This 600 watt High Output HPS bulb emits 95,000 lumens - standard HPS bulbs which emit only 88,000 lumens. Perfect for 600 watt HPS grow light systems This bulb gives you a higher light output which equates into faster / more plant growth and ultimately higher plant yields.
which do you think?