I put together a commercial system, 9,760g over about 110 tanks, designed by DAS (Dutch Aquarium Systems). We used large sponge filters, one per 20 or 30g of water (inside a corner chamber which also housed the heater), air driven from 2 rotary compressors. The water change system consisted of a regulator valve (supply constant pre-set temperature) feeding a carbon filter (about 2cu.ft. to remove chlorine and break down chloramine), feeding a bank of valves & pipes (all controlled by a generic automatic lawn watering controller available at reno stores), feeding the individual tanks through 2" PVC to a flexible rubber hose to the tank. All the tanks had drilled overflows to the drain. I programmed it for four 5g water changes per day (every 6 hours). While this is certainly overkill for a home fishroom, it utilized a lot of inexpensive elements which worked quite efficiently, and it was able to comfortably hold obscene amounts of fish in species tanks.
The elements which I would take to a personal fishroom are the sponge filter system (perhaps with small powerheads), drilled overflows, carbon filtration, and instead of a temperature & time controlled water change, I would use a constant drip system (which requires no temperature regulation other than whatever heaters you're using (tank or ambient) and the lower flow rate allows the carbon to operate much more efficiently).
I'm not keen on central filtration systems for FW. They have a number of vulnerabilities and limitations.
hth
