migration sql 2003 to 2008, Sql side and php side
There is no MSSQL 2003, so you must mean MSSQL 2005, right? Are you trying to upgrade? Do you have a development environment you can test in? That's your best course of action. Other than that, I'm not sure what you're asking exactly. 

But I've upgraded from 2005 to 2008 using a PHP environment before and nothing broke. There might be some deprecated features in 2008 but as far as I know they haven't been removed from the engine, just deprecated. Most everything should work. But again, try it out in a development environment.