Wow, 34 Hz. I would stay away from the Dali subs, they are made for music, but you will miss quite a bit of deep bass in movies.
The tuning frequency of subwoofers applies more to ported subwoofers, not so much sealed subwoofers. In a ported subwoofer, the ports give a strong boost to output all the way down to their tuning point, which is the port's resonant frequency, but under that point output rolls off very fast, so you don't get much bass below tuning, as opposed to a sealed sub which rolls of gradually and can produce significant, if lesser, output below the driver's resonant frequency.
The tuning point for the XTZ sub looks to be just below 20 Hz, whereas in the PB13 and PC13, you can adjust the tuning point by sealing one of their multiple ports. The tuning points can be 20 Hz, 15 Hz, or 10 Hz. The only difference between the PC13 and PB13 is form factor. They will sound the same. The cylinder doesn't look as nice, but it's has a much smaller footprint and is lighter, so it's a bit more practical.