Mid-fi integrated tube amp advice

Perhaps start with a hybrid?  This one is well regarded and I can speak from experience that it is a nice unit at that price:

https://www.audiogon.com/listings/lis8gbgh-unison-research-unico-nuovo-amplifier-hybrid-tube-integra...

Another option that is full tube with built in phono and dac:

http://www.usaudiomart.com/details/649421814-ifi-audioretro-stereo-50el84-tube-integrated-amplifierd...

Also check out the Yaqin integrateds, but stay away from the hybrid designs.

The unit you linked would worry me about quality due to the built in 'meter tubes' on the ends.  I've never heard of the brand which gives me more pause as well.  The products listed above are much better choices - I'd probably go Unison, then Yaqin, then iFi as the iFi might be just a little shy of power for those q900.

ihor, I think you missed my recommendation of that same amp two responses prior.  Regardless, that's two 'go aheads' for the Unico.

Jolida favors more of a solid state sound to me. I agree with the el34 recommendation given the speakers.  Yaqin might be your best bet, but if you want something with a little more QC here in the US, check out Silk Audio.  It's basically a rebadged Yaqin with support this side of the Pacific.

Congrats buckley!  Yaqin does not have a distributor in the US (officially) so you won't find any professional reviews.  On the flip side, that is one of many reasons why they are as cheap as they are.