Devialet with waterfall niagara part of surround set

[Wills1831]

Hi everyone,

I'm currently looking forward to buy a devialet amp that would suit my current speaker better.
I'd like to have some opinions and eventually get some advice.

My current setup is a Marantz sr7011, great amp but which doesn't do justice to my speakers. The Marantz is used to drive 5.1 channels.

My idea is to add a devialet 200 or 250 to drive the front speakers (waterfall niagaras platinum) in stereo mode for when I listen to music (which i do a lot and from all types music), and activate the Marantz when i need the surround speakers to come into play. (Both would be hooked up by rca interconnect - i've read all is programmable on the rear)
Most likely i'll hook the sub (bk xxls400) with specific speakon cable on the front channels, so that i have some bass during stereo listening.
Marantz will do the decoding when playing movies and passthrough signal via the rca to the front, while sending signal directly to rears, center and sub (lfe).

i don't think theses waterfall are SAMed (not sure that's an issue).

Does this config makes sense ? I struggle to read reviews pairing up devialet and niagara, although niagaras speakers are atohm which I believe should play beautifully with devialet.

Any feedback is welcome.
Budget is tight, so i might consider buying used.

Thanks
W.