TempDB on Solid State Drives on SQL Server Cluster
Previous to SQL 2012, all SQL Server files had to be on a shared cluster resource.  It's not so much an issue of the recognition of a local path, but just that SQL Server won't allow you to use local storage in a clustered installation.  This is problematic for SSDs because it is usually to expensive to attach SSDs as anything other than direct attached storage.  With SQL 2012, you can now place TempDB on local disk.  You can still use SSDs, they just have to be added as a shared cluster resource.

Are you 100% sure that you can't upgrade to SQL 2012?  SQL 2012 will support SQL 2005 compatability level, meaning your code will be executed as if it were SQL 2005 but it will be on the 2012 engine.  There might be some other hurdles, but this should address the application interface.  Caveat of thoroughly testing applies.