Yes, the graphite lube would be good, or a nice "light oil".
Just be careful with silicone. It is very difficult to get off of parts, especially if you are going to paint them. They won't allow silicone lube of any kind in an assembly plant as it is so hard to clean and makes problems for any paint repairs (causes fish eyes).
Maybe use a teflon spray like Tri-Flo(w)?. I've seen it at Ace hardware stores.
Also pay attention to how you route the cable. Sharp bends will make it tighter. Try to use larger radius bends when routing the cables whenever possible. Like porting heads, the more bends you have the more resistance it will have. Straighter is better...