Bookshelf are nice if that's what the room and budget will fit. I have rb61ii as back speakers and I have owned many reference line floor standers including rf82. The rf82 will give you a much better front stage than the rb61. Sub or no sub it's night and day. Even crossed over at 80hz the rf82 will give you a bigger more effortless sound. Still a lot of bass above 80hz and the rf82 will outperform the much smaller rb61. My advise is the rf62ii and rc62ii.
Klipsch Pro Cinema KPT-904 L/C/R, Pro Cinema KPT-1201-T2 for sides and RB-61 II for backs.
SVS PB13-Ultra, PB12-Plus x2, and Velodyne SMS-1 Sub EQ
SC-55 elite and B&K 200.7 S2
JVC RS-45 Projector, and Seymour CS 125” 2.35 screen
Oppo BDP-103 9 ATS Acoustic panels