North American suppliers of intercom products are moving in this direction but do not seem to be in a rush and are providing it as an add-on vs. redesign from scratch; understandable but short sighted.They don't have a lot of distribution / installer network in the US but depending on your technical skills, not that hard to install yourself.

Suppliers I useMountain states plumbing supply Great western plumbing supply Standard plumbing supply My 2 cents

Will be difficult to find a supplier willing to sell you the system without that licensing.Mark

If you contract out, I would highlight not getting locked into a long term contract, no negative option renewal and keeping in mind that the supplier has to make money as well.The contract I signed was for 3 years, explicit renewal after the initial term with an out clause if they do not respond to 2 emergency call outs in a row within 24 hours, flat monthly fee for all servicing and emergency call out and a laundry card based system (reverse ATM) included.

@Sue Matt In order for a paint supplier to release that kind of pricing, they would have the access to a large commercial account that does business countrywide.

You can buy them at local suppliers for a lot less.

I also am lucky in that my father-in-law works for a plumbing supply company (they supply to contractors/plumbers only) and we can get HVAC/plumbing/bathroom remodel supplies at their wholesale price so we will save a lot there compared to big box suppliers. 

My only advice is that if you have multiple rentals, paint them all the same shade of grey and always buy from the same supplier, which makes it easier to repaint or do touch ups. 

Make sure to call or check the website of your water supplier.

Rabco is another pretty major metal building supplier that works on the east coast that might be a good group to talk with.