@Webb.Peter, First off great job on the build the pictures looked great.
I have a couple questions I hope you can answer for me, or at least confirm my evaluation of the system. My current understanding of the light panel is as follows:
24: Red Modules, 1.5W/unit, 12V supply voltage, total ~36W
8: Blue Modules, 1.8W/unit, 12V supply voltage, total ~14.4W
10: White Modules, 1.32W/unit, 12V supply voltage, total ~13.2W
Total Light Module Wattage ~63.6W
For the life of me I couldn't find a wiring schematic for the lighting modules. Are the modules wired in parallel supplying 12V per node, or is there a 24V rail requiring a series parallel configuration of the lighting modules? I only ask this to steer my design considerations for the module, if a 24V or 36V rail is available a linear constant current source would be acceptable with minimal loses, but if only a 12V rail is present a linear constant current source (like a resistor in GE's case) doesn't make sense as we would take ~25% converter loss before even creating one photon. The higher the input voltage the lower the converter loss in a linear system.
4 Independent lighting panels with 36 LEDs on each panel.
4 panels would take the place of 42 modules cutting the wiring the down from 82 wires to 12.
I have spoken with my contact over at Khatod and he recommended the following optic: http://www.khatod.com/Khatod/PublicTempStorage/knac36xxads_technical_detail3162871228305.pdf
This can be outfitted with a silicone gasket to give the appropriate IP rating. Cost-wise they should be around $10 a piece.
Mid-Power LEDs either the 757s from Nichia or a horticulture line of LEDs from Lumileds. The advantage of the Mid-power LEDs is two-fold cost and efficiency.
I am still working on costing for the unit but my goal is to get the price below $25 a piece (don't quote me on the price yet).
Please any feedback/questions anyone has are more then welcome. It is always nice to get an alternative viewpoint whenever designing.