Yo.

Been looking through the CS, but I can't find any of those dock pier things without the support pillars coming underneath them. Do they exist?

Cheers in advance.

Try ex_common_plat_LRG or others of that type.
Or in_cavern_ramp00
A great index of most CS items can be found http://tommyshideout.net/files/srikandi/TESCSItemIndex/

You could also chop the posts off yourself in a 3D render program like Blender or NifSkope. They are free.

Thanks man.