I've had my Epson 8350 projector for numerous years and absolutely love it. I'm ready to upgrade to bigger and better things though and have my mind set on the Optoma UHD60. I have to upgrade my receiver obviously for it to take advantage of the 4k signal. The receiver I had my eyes on was the Onkyo TX-RZ920. I don't completely understand if this receiver will work with my setup though. I currently have a 7.2 setup and plan on adding 2 ATMOS speakers. This receiver I'm looking at states that it's 5.2.4 or 7.2.4 with an outboard amp. If I get this receiver will I have to get an external amp for the ATMOS speakers? Or will this receiver run my 7.2.2 setup without an amp???? Please help!!!!