Also reading all of this babbling that’s going only. A lot of it is actually good advice but at the end of the day, it’s your ears, your room, your setup with wall panels or not, in another words, your decision. You asked what the differences would be for the two Pass Labs amplifiers. One is fully Class A and the other is Class A that switches to Class AB. Right off the bat, that’s a different sound. You’re speakers are ported so power is definitely not the issue. If they were sealed, then I can see the need for the Pass Labs X250.8.
SPECIFICATIONS
1 Sensitivity in average listening room
34Hz - 20kHz
102dB @ 2.83V / 1m
100W/400W
119dB Continuous
8 ohms Compatible
HF: 5000Hz MF: 700Hz
K-107-TI 1” (2.54cm) Titanium diaphragm compression driver
K-702 1.75” (4.45cm) Polyimide diaphragm compression driver
K-33-E 15” (38.1cm) Fiber-composite cone woofer
MDF with fine veneers
Understanding the potential of your equipment and it’s limits makes a huge difference to help you get to the sound you are looking for. Hope this helps and best to luck with your decision.