Solution for incoming calls small bussiness

Hello gents,
Need some insights in this matter.
Scenario: a take away place where 2 are attending the sale and calls are incoming from land phone and from a smartphone.

What is needed: A device (Plantronics or similar) who can connect to both land line and smartphone and take the calls from both devices and features a wireless headphone, so that the calls can be attended everywhere in the sale area.

Solution: Doesn’t have to be cheap. I need something good, reliable. Also, I wonder if there is need for a digital central for incoming calls.

Thanks for your time,

I use Microsoft Teams for my business. It is solid and provides all the features needed for a small business.