Telephone PBX + intercom

["martinpalmer8" <martinpalmer8@xxxxxxxxx>]

Can anyone suggest a source of the following, please?

I need a telephone PBX for my home with two incoming lines and six
extensions.

I also need an intercom for the back gate at the bottom of the garden.
When a visitor presses a button on the intercom, all the phone
extensions in the house ring. Someone in the house can pick up the
nearest phone, talk to the visitor and press a phone key to operate
the gate release.

I heard that Panasonic might do a suitable PBX but I can't find
anything on their website.