The Alpha 10 will work very nicely in a 2.5ft3 box tuned to 40Hz. That's close to the volume of the (non-tower) two π speaker.Personally, I like the sound of the KSN1038 tweeter. The thing is that with it coming online at 3.5kHz, the Alpha 10 is required to work up that high. It does so, and is actually pretty loud at that frequency. So you really want to be sure to add the 0.5mH coil to tame it there just a bit.
But I'm pretty find of those speakers. I'd say go for it.