Sevens name exercise is really a great idea. I profess to not having heard of that one before.
We were quite lucky though in regards to names. We picked the name as soon as we choosed the dog and our breeder starting calling the dog by that name. With Flute, her kennel name had to start with a G, so we called her Georgous Flute and told our breeder that we would just be calling her Flute. They just started to call our girl Flute right up until we picked her up, so she was well used to it.