An overflow box will work fine. I've been using one for several months and haven't had a single problem. The pre-filter in the box is very easy to access for cleaning.
Your cycle rate is dependant on you pump output and your head height. Typically, tanks need to have the water pumped about 3' up from the sump.
Make sure that your overflow box is big enough to handle the flow rate of your return pump (at your head height) or the display tank will overflow. For a 55 gal
tank that should be no problem.
MarineDepot sells overflow boxes that look very good. I have one made by ProClear Aquatics that looks clunky but works perfect.