
New amp is great and can well power up to 4 speakers that are 8ohms. Only 2 speakers of 6ohm.
Most speakers are 8 ohms, so it's most likely not an issue. You can check the specs for the models to be purchased to be sure. If they are not 8 ohm, you can look into getting a speaker switch.
Sonos is designed to work under normal residential wifi, and sometimes having a lot of bodies in a space can interfere with a wifi signal. However, if you're network is going to look pretty much the same as it did in your old shop, you shouldn't have an issue.
Thanks Danny! Would myself or the electrician be able to install the amp or would I need a professional installer? Thanks a million for all the help!!
The electrician should be putting in a wall plate with stereo binding posts like this: