60 million rows is not beyond SQL's capabilities. I've had more than that in a single table. The design needs to be done carefully, but it is possible.
Are you expecting 10 million more rows per hour, per day, per month?
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