thats awesome. thats exactly what i will be doing soon with my discus tank-40gal. i like the plain set up. i had a planted tank with my discus but had too many problems with plants and high temps and debris. i currently have one dlue diamond, a small red turquoise and a red turquoise/blue diamond mix (i think). planning on getting 2 more. maybe a malboro red or pidgeon blood and a red melon.
i am only gonna put in a centre piece drift wood and gravel and paint the back black, then add a school of 6 cories. i aslo like the skunk cories but they are a bit hard to find here.
your tank doesnt look overcrowded, even when they grow out i think they will be fine.