KEF KUBE 10b or 12b w/LS50 Wireless?

I’m thinking of picking up a sub for my KEF LS50 Wireless speakers and am eyeballing these two.  The room in question, my man cave, is about 15’x15’, about 10’ ceiling. The speakers sit on my desk about 60” apart.

Is the 12b overkill or will it work well? I’m sure the 10b is enough but for another $100 I can have a setup that can move into a larger room later if I want.

Thanks for any input.