Then it is an easy decision for you, in the US and Canada, the Cinema 30 costs about $1,000 more when not on sale. When on sale, the AVR-X6800H had been down to C$2,999, and that would have been US$2,000!!
So, a big congratulations to you landing one of the best available AVR for $3,730 net.
For subwoofers, I know I am biased, I like SVS as a company so I would recommend the SB16-Ultra. The PB16-Ultra is much more capable but for that you will need a large room and proper space for that gigantic 175 lb.