Thanks for your reply.
Firstly, should I start a new thread, I don't want to hijack this one if not appropriate

You are correct each unit has 50 x3watt LEDs (25 white/25 blue).
I am not sure what you mean by 12 leds per driver ? Would i not just need 1 driver for the white and 1 driver for the blue @ 75 watts per driver.
So for the total of 3 units I would need 6 drivers ? Or am I missing something.
Please bear with me I am just starting out with this and have a LOT (everything) to learn