Eheim 2217 is the way to go, starting out just replace the kix medium with seachem matrix which is 2-3 times more effective giving you the equivalent of about 25 gallons worth of bio balls in a small low power package. I'd pair it with an Aquaclear 70 or 110 hob for surface agitation.
i actually run an
- eshoppes wet/dry for primary bio-filteration,
- a 2217 loaded with blue foam for
- an AC110 hob with foam/floss for mechanical filtration/polishing/surface agitation,
- an AC70 powerhead w/ micron filter for current and fine filtering
- and a Maxijet 1200 for flow/circulation for my overstocked 70g african cichlid tank lol