The OPPO would replace both the Sony 777 and the Sony 550. That's one of the really big benefits of the BDP-83: it can do Blu-ray (decoding for all formats), SACD, DVD-Audio (once it launches, although the EAP doesn't have that yet), and kick-ass with standard DVD. You connect the BDP-83's 7.1 analog output to the 990 along with a coaxial or optical so you can use that with DVD's and CD's if you like, feed the HDMI video to your projector (either directly or through the 990's switching if you have a DVI/HDMI cable or satellite receiver), and let the 83 handle all of your optical disc needs. Sell the 777 and 550, and you'd end up spending very little overall.