I'm obviously very late to this thread, but for anyone coming this way in future…
I also have a pair of 8000S and SX amps, and would wholeheartedly recommend bi-amping them.
I really enjoy mine with some Neat Mystique II speakers (small floorstanders), and have actually spoken to Bob Sturgeon (founder of Neat) about this. He asked me what I was running them with, and when I told him Bob said "bi-amping does make a difference, doesn't it".
These days a lot of manufacturers seem to be of the view that bi-amping doesn't make any difference. Maybe their designs are different, but with these 20 year old amps, the difference is quite noticeable. Subtle, but noticeable.
Coincidentally, I also use LMS with piCorePlayer (such a wonderful system) and also used to have a pair of Mission 782 floorstanders! They were great, but too big for any of my lounges. Hence the Neat's.