ThanksI think the ClassicLED has more LEDs, so the light output is higher, but it uses more power than the SlimLED. Similar price for the same length of light.
Your plants are low light demand, so they don't need the high output. Ive kept your plants with no aquarium light at all. Both lights can both be programmed, so if you are OK with the higher energy use I would go for the ClassicLED and run it at a lower % output if it was too bright.