Consider using GUIDs/UUIDs instead of integers. GUIDs are friendlier for replication, fake/mock data, and other reasons. The only situations where I'd recommend against using GUIDs is if total row size is a concern (GUIDs are usually larger on disk than integers) or if there is some legacy requirement to use them (e.g., an integration with a third-party).

Another thing I've done is use GUIDs for the primary key, then have an identity/sequence column called something like Sequence, which retains the sequencing capabilities of a regular integer identity column.