Well, with the Google AIY kit, as it's Raspberry Pi based, you have the ability to do what you want with the hardware. It's really just a microphone and speaker on top of it.

At some point you could run offline models to take voice input and output intent. What you then do with that is up to you. What the cloud services provide are common lookups, such as searching wikipedia, your calendars, etc. You'd need to implement that yourself.

AWS DeepLens seems to run Ubuntu 16.04 under the hood, but it's unknown whether you can get SSH access to it. If so, it's could be a really nice hackable camera on which you could run anything you want.