You can download the music to most of FRD's games at their official website, including the Timesplitters series. Here's a link:
http://www.frd.co.uk/downloads.php
Just look under the games name and click on music.
Nice find but they don't have all the tracks that are on the soundtrack I downloaded.
E.g. the site doesn't have the remix of the Siberian Chopper music.