Tons of graphics and other modpacks are publicly available on these forums! Just go to the 'Creation and Customization' section; you can find scenario's, graphics modpacks and unit graphics there.
Not many scenario's are for Vanilla, though. Units will fit in any version of Civ, and many terrain modpacks will have a Vanilla version. You will probably find something you can use. If you still have a question about installation or something, it's best to ask in the main 'Creation and Customization' forum.