Hi,
Could you explain what you think better dynamics is/are to us since that's your motivator?
You're 6~8 feet from the speakers. Also, you're using a crossover most likely for the sub and bass management. So what dynamics are your towers affording you that bookshelves cannot? Your towers are literally operating as bookshelves on their own built in stand since you're using a crossover. The additional sensitivity of cabinet volume is also largely irrelevant because of the listening distance, you have plenty of power.
Your Klipsch are "suggested" to be 96db sensitive, but they're likely less. But they're at least 90~92db sensitive. Let's just use 92db as a safe baseline for sensitivity on them, at 8 feet distance (also generous in your space). Let's ignore several speakers and boundaries and just look at 1 speaker's potential if it were in an anechoic chamber basically (so lower output than in an actual room near a wall). For just 10 watts, your single speaker will output 94.3db. That's loud! You get +3db for every doubling of power. So 20 watts gets you to 97.3db. 40 watts gets you to 100.3db. This is very loud! 80 watts gets you to 103.3db. 160 watts gets you to 106.3db and that's louder than THX reference peak levels and will damage your hearing. So at this distance, you simply don't need big towers. This is where "dynamics" comes from, having a relationship of sensivitiy, distance, power and resulting SPL at listening position so that you're not clipping. The more sensitive the speakers, the more SPL they can manage for a given amount of power. Since you're at 8 feet, you can use nearly any speaker and get loud. It becomes, how loud do you need to be? Is 85~95db loud enough? Or do you need 105db THX reference peaks? This question is how you figure out what you actually need for "dynamics."
At $3k you could go end-game on nice bookshelves ($1k each as a budget). If you want real increase in dynamic range potential, it would be with something with the highest sensitivity such as DIY 1099's or PowerSoundAudio 210-M's. If you just want higher quality in general at your budget limit, it will come from an excellent bookshelf or mini-tower, such as Philharmonic BMR's (get 3) or Ascend Acoustics Sierra 2EX's (get 3), all of those have RAAL tweeters.
Very best,