You will need two Amps and four speaker for the front and rear channels as well as a Sub

If you don’t want to go with two amps, you could get a single amp, passive speakers for fronts, , a Sonos sub or third party sub and a pair of any of these speakers below for rear surrounds 
 

• Era 100
• Era 100 Pro
• Five
• One (Gen 1)
• One (Gen 2)
• One SL
• Play:1
• Play:3
• Play:5 (Gen 2)
• SYMFONISK Bookshelf (Gen 1)
• SYMFONISK Bookshelf (Gen 2)
• SYMFONISK Floor lamp1
• SYMFONISK Picture frame
• SYMFONISK Table lamp (Gen 1)
• SYMFONISK Table lamp (Gen 2)1

1The SYMFONISK Floor lamp and SYMFONISK Table lamp (Gen 2) are related models and can be used together as surround speakers.

https://support.sonos.com/en-gb/article/surround-sound-guidelines-and-limitations?product=amp