New Tank - Critique Please

[TheReefGeek]

Setting up a 20g bowfront, dimensions 24"x12"x18"

Lighting: 2x75w VHO, 1 10K, 1 actinic
DIY hood - no reflector, just URI internal bulb reflectors + white canopy and a 3" fan and vent hole.
DIY overflow - Corner overflow with Durso standpipe to cut down noise.
Sump: 10g or 20g tank with 3 baffles to fight microbubbles
CPR bakpakII skimmer off 10g sump
DIY auto top off from 5g reservoir
Fuge: Aquaclear 500 off 10g sump if I can find one used
Water flow: Eheim 1250 return pump + small quiet one pump behind rockwork
30lbs live sand for DSB
30bls live rock

Intended inhabitants:
Unknown, depends on what 2x75w VHO can handle in a small tank like this.