Well the obvious answer is get the same spec as you currently have. We can look up what that bike's specs are publishes as being but going by what the bike actually has is more assumption proof Since the BB isn't an issue causing this need I see no reason to not continue the same kind but with less worn stuff.

The reason to go to a brand like Rotor might be because they offer non traditional ring shapes and/or their ring/arm rotational changing design. Both are rather independent of the looks. I suggest you decide what function you want first, then what fits and go from that point with what looks good. Andy