AVA Vision Set 400 v Belles SA-100

What amp would you recommend of these two, AVA Vision Set 400 or the Belles SA-100 amp, to be used with either a Don Sachs pre amp or a Supratek Cabernet pre, my speakers are Graham Audio LS 5/9.

Would very much appreciate your input on the two amps, especially how they fair with tube pre amps.
What is the sound difference between them and is there a quality difference?
I know that the Belles is much more expensive, but I can maybe make a deal on a demo unit, that puts it into the same price bracket as a new Set 400.

I don’t like clinical sound, or thin upper mid/treble, I prefer rich and organic sound with clarity, but never harsh,
also it is very important for me to be able to listen for many hours without any fatigue.

Hope to hear from some members that have or have heard either amp.
Quite many watching, but not any reply’s, so a little bump before this one goes to the history web...
Not much help, but I've heard the SET 400, and (many times in different systems) the Graham LS5/9. I can say the SET is not a harsh amp. It is clear, very dynamic, but organic sounding. If you don't mind the prospect of a 30 day trial with the risk of paying return shipping, I think it would be worth a try in your setup.
Thanks for your input, I live in remote islands, so not easy to try before buy, what other amps would you compare the Set400 too ?
IME the closest I've heard would be the Pass X series, specifically the Pass X250.5. Different systems but speakers from the same manufacturer, so it isn't a side by side comparison. Tough call as to which amp was "better". SET? Maybe a bit faster, more dynamic, very linear, very good articulation across the range, a nice sound. Pass? Maybe a bit smoother, a bit more articulate in the low end, a slightly sweeter high end, fleshier midrange, again a nice sound. I could live with either one.