I also really like the Stage four π and seven π speakers, using the Omega 15. It is a very powerful and clean woofer, even without a shorting ring. Since you're only going to be driving it with 10 watts, the woofer is going to be loafing along. That will keep distortion way down.

The Premium Series four π and seven π speakers use the Kilomax 15. It is best when you're going to be using a little more power. It sounds great at moderate and low levels too, and some prefer it. But it is made for all-out power and I think it trades maybe a bit of lower level detail refinement for maximum output capabilities.