I'm looking for a kind of plastic that resists static build up. Or, some kind of permanent spray/coating that would resist static build up on plastics. Any ideas?

 

Not enough information.

Static has more to do with the environment than the object. A brick-sized block of plastic sitting on my desk is not going to take on a static charge regardless of what touches it.

However, the nylon membranes that are on my legs (hosiery) do occasionally attract a charge especially when in contact with a wool skirt.

So...it would depend on the object in question, its use, and its environment.

 

My understanding is that anything non-conductive can build up a static charge. Basically, any extra electrons that get attached to the material have nowhere to go.

So to avoid building up a static charge, you need to provide a conductive path to drain the electrons... Carbon fiber might work for you, depending on the resin and coating - the carbon is a conductor. (I've read that it can cause corrosion on metals because of that, much like salt water.)