Is bi amping worth it ?

@OP - am I correct that your loudspeakers have two sets of speaker terminals for bi-wiring/biamping. If that is the case you don't need a separate crossover - you will just be passively biamping, feeding the signal from your preamp to two separate sets of amplifiers.

However, as I regularly say here, you have to consider opportunity cost. What would a better amplifier sound like versus a bi-amped set?

As mentioned by other posters, Klipsch's do not need lots of watts so I would be inclined to believe that better watts would be preferable to more watts.

@OP. Your preamp has multiple pre outs, so you can easily bi-amp without an additional crossover.

The pre and power are perfectly fine, though a high quality solid state class amp of lower power would be a better match for the speakers. I say solid state because the speakers have a very demanding modulus of impedance in the bass.

However, from your description of what you are trying to achieve sonically, the problem is that the speaker is quite uneven in the mid to upper bass and has a very rapid falloff lower down. Bi-amping is not really going to help you because it's not going to correct or even ameliorate the fundamental issues in the bass referred to above.