It's a pierce weapon, so it already lends itself to working well with a lower PS than full strength, and I'd recommend getting at least 5 Athletics with it as it's really short, any competent player will be able to easily walk out of range of a full strength build using a Bec. I'd recommend going 18/21 personally, maxing Ath and PS and adding IF, WM or other skills to taste. Balanced builds work really nicely with it.