LEDgardener

Could I add some supplementary red leds to my build on the same driver? And how many EB strips would be good for the xlg-200-24a

8 watts per foot of strip is a good value to work off. It depends on how much you want to spend. In a 2X4 I would put 12 2 foot strips or 6 4 foot strips, the 12 strips would give a better spread than the 6.

My budget is about $100 for driver and lights. The aluminum and other bits I get for free. 12x2ft strips is about $58 xlg-200-24a is $40 to which is on budget. What would you do with that budget in a 6.5ft2 space?

I hooked the xlg200 drivers to 6 strips, they are nowhere close to their temperature limit, but I guess I'm running them pretty hard.
You could add some red, or UV, but I guess your budget would be pushing you towards red. Cutter has some wide phosphor converted reds that cost 1.5$ a piece, that cover 630-850nm, and some of the last gen red strips are 20au$, so 2 would maybe fit in your budget without shipping costs.

If your in the US, then steves led also sells some pretty cheap discrete diodes.