SQL Packager produces executables by modifying an existing Visual Studio 2005 project -- the "template" project -- which exists in SQL Packager's installation folder. (%programfiles%\\red gate\\sql packager 6\\sql packager code templates\\c#). If you want all packages to look the same, you could modify the project files (after backing the factory version up first, of course!).
If you want to edit the project using VS2008, please ensure that you back up the project and that your packages compile successfully. Many years ago, when the template was done is VS2003 and users wanted to upgrade the template to VS2005, they found that the packages wouldn't compile because SQL Packager itself was still building the resource files containing the SQL code in VS2003 format, and VS2005 does not automatically upgrade the resource files. I'm not sure if this still happens when you try to compile VS2005 resources in VS2008 projects.
I hope this helps.