Just a little warning that it is risky to drill tempered tanks .. the glass tend to shatter. <I did a side drill/cut on an old tank once & it eventually cracked from a minor imperfection on the cut line ... so I am using a HOB
# of bulkheads: Look at this one:
BeanAnimal's Bar and Grill - Silent and Fail-Safe Overflow System
That is a 3 drain system for quietness. That would be the max you would need. I use a modification (actually the original design) of only 2 standpipes. <combining the emergency & startup.>
80 gal FW with 30 gal DIY wet/dry/sump.
9 fancy golds, 1 hillstream loaches, 1 rubber-lip pleco (C. thomasi), 3 SAEs, small school of white cloud minnows, planted.