There is no replacement for extra more lights. You're running 1200 watts on a 8x4 tray, which most people feel is too low (37.5 watt per sq foot, sorry, US Standard system is crap).
2x1000 or 3x600 would be ideal. The rails have to be mounted correctly on the ceiling or any type of overhead bar. In addition, if you're aircooling the lights, it makes ducting really difficult and prone to tears since the ducting will constantly flex.
I was able to successfully push 3 hoods using one lightrail 3.5 motor.