No, you can't get 8 ohms with 4 16-ohm speakers. Here are the possible wirings:
+o-+o-+o-+o- all in series: 64 ohms |+o-+o-| |+o-+o-| series parallel: 16 ohms |+o-| |+o-| |+o-| |+o-| all in...
You can sure, the issue will be the amp driving the speakers, an amp with a low impedance output will be very inefficient with these speakers. So ideally for a effective and efficient system, it's...
It depends on the application. If you have an amp that is stable in 8 ohms per channel, then 8 ohm speakers will work best. However, if you wanted multiple speakers on that channel you could use two...