I'm planning on asking my sister & brother in law to be the godparents to my two kids, only thing is…

I'm planning on asking my sister & brother in law to be the godparents to my two kids, only thing is I live in Texas & they live in California (he's in the Air Force) so I'm not quite sure how to ask them? I wanted to FaceTime because he deploys in 3 weeks & comes back in March... & I want to be able to ask them together😐 any ideas of how to make it unique?