The UK alarm market sucks from a smart home perspective.
I had a look at what I believe is the Era website and could find no mention of Alexa and Google but several of the reseller sites do state this.
The Lightwave support allows the Era system to control Lightwave products like lights. It will not make it any easier to connect to Smartthings.
It apparently also supports IFTTT so that would be one way for Smartthings to control it.
This Era product whilst not to my taste does have some plus points over other UK offerings. It has an outdoor siren although only solar/battery rather than wired, it has a doorbell although only its own proprietary one. Similarly it only supports its own cameras.
Another similar one with some Smartthings support is the Simplisafe
Some of their options are not available in the UK.
There are I believe one or two UK models which support Z-Wave but they do this by acting as the hub and hence cannot be linked to Smartthings.
I recently came across Abode
It is not yet available in the UK but they are now owned by an Italian firm and seem to be indicating plans to expand internationally.