Blurays are not dvds. Different tech altho modern bluray players can generally play dvd and cd as well as bluray (and some other optical disc formats).
Your old gear is only capable of lossy 5.1 codecs it seems, not sure about your multich analog input capability if you get an optical disc player with a full set of analog outputs (and those tend to be expensive, too).
FWIW OP has these units:
www.hifiengine.com
www.hifiengine.com