I used the e-voice for many years with a gov domain. 

Joe has a helper sheet on external domains, which is here.

https://e-voice.org.uk/documentation/community/domain-name/

We used https://www.cloudnext.uk/council-hosting/ to buy a gov domain from.

They are part of the domain helper service and I understand this an get you a discount on the first registration fee. They can also help point to the e-voice site.

I would also suggest you make sure the site and the content meets WCAG 2.1.

James (clerk at Stondon Parish Council)