It's been a while since I've used my motion control gear. I have the Dynamic Perception Sapphire Pro Pan/Tilt head and a 40" slider. Any guidance on how to estimate how many frames to shoot to go the length of the slider and get smooth (not choppy) footage? Is there some kind of standard calculation that anyone uses for this, perhaps based on focal length, etc?

It depends from how close you are to your foreground. I'd not worry too much about the speed of the movement. I'd decide for the number of frames (for example 600-800) and then go for it. Make your experiments and you will learn what looks good.