To restore master you need to take the server down, restart it in single user mode, restore then restart again. Running scripts to create logins requires no downtime at all. If you're going for minimal downtime, why are you looking at restoring the backup of master?
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability