It’s a handful for most AVRs. I had the older Onkyo, the 876, about 50 lbs, but not sure about the Onkyo txnr809. If it has Pre outs, you could get a 2 channel amp later on.
I have the Q750, and the Kef house sound for this line tilts to the warm side slightly, with great imaging and detail. All the better if you can get the Q950 on sale, I received a steep discount last December.