My cousin's winning 180g...uses my 'low wattage' approach for high performance...
180g w/ only one overflow.
3x250wattHQI/DE halides with Pheonix 14,000K (6 hour photoperiod).
6x54wattT5s (staggered to cover whole tank), 2xactinic, 2xblue+, 2x6500K.
Eheim 1250 as return pump (only 200gph through overflow/skimmer).
Aqua Medic 5000 baby direct fed from overflow before water passes to sump.
40B sump, half of which is refugium (I forget what its lit with, bu its about 7 species of non-caulerpa macro algae).
Phosban reactor.
2x Ebo 250watt heaters in sump
2xTunze Stream 6200s in tank for flow (thats over a possible 10,000gph for a mere average of 55watts!)
No chiller (just fans over the open top of the aquarium)
DIY Top-off (Hes a biomedical engineer, so can make better than you can buy)
Deltec Ca reactor.
I wouldnt change a thing except maybe switching the lights around a bit...but thats all personal taste. His tank is amazing.