Good sound is to the ear of the beholder.
Whether you'd like this...
http://www.zuaudio.com/#definition-mk4-loudspeaker.php
or this...
http://totemacoustic.com/en/hi-fi/compact/rainmaker/
or this...
http://www.wilsonaudio.com/product_sash.shtml
Is all between your ears...and wallet.
Receiver=tuner+amp+pre-amp A processor(proper term being pre-pro...ie, pre-amp processor) is just the pre-amp and tuner. You buy the amp(s) separately. It is generally less expensive, long term, to buy a pre-pro if you are spending $2000+ on AV equipment every 5 years(the timeframe when the next...
The AVR is purchased based on your needs. If you buy 8 ohm speakers, you can buy any AVR ever made. 95%* of the speakers ever made in the history of audio dating back to 1870 will go with 95% of the amps/receivers/AVR ever made since 1905. (Yes speakers and "home audio" have been around that...