Get a NHT X2 active crossover and a pair of NHT A1 monoblock amps to bi-amp the 2.9's subs. They are much better than the older SA-2/SA-3 amp/crossover combos. This will also give you more control over the bass by allowing you to dial in flat response for music, and at the same time, a little extra "boom" for movie soundtracks' LFE content. Then, for the 2.9's upper frequncy drivers, since they are high passed at 100 Hz, power rating simply isn't as critical. Go for quality over quantity.
Also, replace those dipole HDP2 surrounds with a pair of new Evolution L5 on wall surrounds on closeout from ListenUp.com, which are phase-matched to the 2.9s/AC-2.
If you do these things, I guarantee you that you will be happy with your system for many more years to come.