I know that I was trying to push you in the 20g long direction earlier - and I STILL AM...
small, cheap, make a "coast-to-coast" over flow on it - do some custom plumbing so that you can incorporate a SCWD onto the return pump...
by the way GRATS on the kid... i made sure to put my daughter in front of the tank as soon as i could... i'm sure the first thing i saw her follow with her eyes was a bright yellow banana wrasse in my 55g...
glad to see you back, friend!