Looks like you're off to a good start. I love my 60 cube. The dimensions are great for that size tank.
For a return, look at an Eheim 1262. They're practically bullet proof and put out good flow for a 60 cube.
Stocking options. Consider a yellow coris wrasse, one or two fairy wrasses, and/or a couple of flasher wrasses. You can also fit in a goby, blenny, or firefish. The wrasses come in all manner of colors and the majority are peaceful. If you browse through the reef fish forum you'll find great resources on wrasse compatibility. I recommend the yellow coris(It's not actually a coris...) because I had one and he was a model citizen, is bright yellow, and is an active swimmer. I have an orange back fairy that I personally think is stunning though not large enough to be most people's show fish. I've had bicolor and tail spot blennies that were great fish. Same goes for a yellow watchman goby paired with a pistol shrimp. Firefish are colorful and timid at first but once comfortable with non-aggressive tank mates will swim in the water column as well. A lot of choices for fish! Avoid tangs though, a 60 cube just isn't large enough.
