Just bought a house which has the following:  

In the family room, 4 wired infinity ceiling speakers and an in floor subwoofer. 

Outdoors:  2 in ceiling infinity speakers on porch. 

wiring:  all speaker wires run to family room cabinet under the TV. The subwoofer wires are currently connected to a Polk SWA500 amp in the same cabinet under TV, which was left in the home.  The speaker wires are not connected to anything (I do not have a receiver yet). 
 

My goals:  setup 5.1 surround sound for TV.  Add wireless sonos speakers to kitchen and dining room. Create multiple zones for music at least in terms of volume (I don’t need to play one song in dining room and another outside, I just want to be able to turn outside off or at reduced volume versus dining room but they can play same thing). Zones:  family room (wired), outdoors (wired), kitchen (wireless), dining room (wireless). 
 

what is the best way to accomplish this?  Can’t figure out if I should get the sonos amp, the port, a home theater receiver, all of the above?
 

and what speaker is recommended for the center channel for my TV surround sound?  Can or should I use a beam or play 1 for that or get something wired?

thanks

jeff