The feedhorn and LNB provide the best performance as the polarity can be optimized with the servo motor for each satellite and polarity. The Norsat LNB in the photo is still good by today's standards as it is rated 20k. Many of us use feedhorns and LNBs as we can optimize to squeak out every bit of signal from weak transponders or detune to attenuate unwanted interference.
To use the Chaparral feedhorn with the polarity servo and feedhorn, you can manually select the satellite to move the dish actuator motor and select between Odd and Even channels to change the servo polarity. This would need to be done manually for each satellite change and changing channels between transponders on opposite polarities. The simple way to control the Chaparral/servo/LNB would be to use an ASC1 for complete automatic control.
A less expensive option that many hobbyists use is to swap the Chaparral/servo/LNB feed and instead use a LNBF like the C1-PLL. A LNBF automatically changes between polarities buy any FTA STB, but cannot be fine-tuned for each satellite and polarity without going out to the dish and adjusting. To move the actuator motor, use an inexpensive Gbox or Vbox and a FTA STB will control the dish actuator movement for automatic operation.
Edit: I see that you already have a C1-PLL. Measure the existing feedhorn scalar placement, remove and install the C1-PLL LNBF and scalar in the same position. It will be close enough for now, then you can fine-tune and adjust later after you get your feet wet!