u/Careless_Student7764

My dedicated home theater is 20x26x9 feet. 20 feet is the front side with cinemascope screen of 19~ feet width. 26 feet is the length of the room and then 9 feet is room height. Currently i have 5.2.2 speakers. My Denon 3800H AVR supports 9 channel amplification and 11 channel processing. I’m thinking of adding 2 more channels now and then in the future adding a 2 channel amplifier. I have all the 7.2.4 speakers as of now. My question is, should i choose 5.2.4 for now and add an amplifier later for surround back, or choose 7.2.2 now and add amp for 2 more heights later? Any suggestions are appreciated!