This sounds like fun and looks pretty straight forward. Plants dont care about commercial brands or pretty housings--light is light. Custom designing for your personal needs sounds very cool.
to max out a 5x5 for ex. maybe spread out four square panels 'bout 150 actual watts each? or a couple @ 250W each? or??
5w diods? 3?
Those Lumigrow units look pretty cool with the variable adjustments for the blues and reds for veg to bloom shifting. A rheostat for the blues and one for the reds?
Lotta questions re lenses, heat sinks, etc. best sources

first what kinda panel then a parts list eh?