Hmmm. the last person who called me Mr. Murphy was a state trooper. I've looked over the plans you sent me, and as others have pointed out there are some problems. In no particular order, there's the issue of listening position. If you place the towers on a shelf that's above the subwoofer, you will be listening at something like the woofer level. That puts you way below the design axis (the tweeter), and there will be suckouts in the crossover regions, as well as attenuated highs (although that might not be serious). Second, you would need either a sealed design or a front port. And even then you would have to seal off any area to the side or above the speaker to prevent cavity resonances from the tower enclosure you're building. That rules out the Phil 3, because the ported termination of the transmission line is on the top of the woofer cabinet at the back. The Song 3 could be built with a front port. Finally, as others have discussed, there's the issue of baffle step compensation. Forgive me if you've explained this elsewhere, but will the screen be flush with the front of the structural towers? If not--if the screen will be back a couple of feet--then the baffle step compensation issues will be less important. If the screen is going to be flush, there could be a problem. I take it there would be some space behind the screen? If the screen material allows frequencies in the 500 Hz - 1200 Hz region to penetrate at least somewhat, then maybe you can avoid serious problems. If the screen acts more like a wall, then the crossover will ramp down the lower mids and leave you with a bass-heavy presentation. That would be exacerbated by the close proximity of the speakers to the room corners. I kind of have to agree with the others--I think those tower enclosures are going to look a lot better than they will sound. And they will limit your choice of speakers. I cans see a pair of Phil 3's behind an acoustically transparent screen operating smoothly without subs........................ Just saying.
Whatever you end up, I think you have plenty of power.