There are five language installation package for vista SP1 has been released nearly a month, Microsoft released 36 supported languages packs finally.
If you are not going to install the service pack on more than one computer,windows update might be the easier way to download and install it.you can refer for this
vista SP1 update.
Download all language packs. ( 544.3MB)
Download ISO image all language packs. ( 1418.1MB )