You'll get what you are after and more here:
http://stasf2008.ephpbb.com/t6-steel...steel-fury-1-2
Forget about the SPM mod and the unofficial patch - they're usable but have long been overtaken in terms of content. The latest STA mod is the one to have nowadays.
IIRC you need to register on the above site, for all the D/L links to work. Be careful to follow the JSGME enabling order for the different elements, described as the 'installation order' in the above post.
Many of the playable vehicles are illustrated in this thread:
http://stasf2008.ephpbb.com/t22-avai...its-in-sta-mod