Hey there Fritzkrieg,
I do not know much about this figure except from what I have seen everyone elseís customs, but I do know a thing or two about painting plastics. If this figure is like a styrene type of plastic like model cars and such, then enamel paints would be the best. Durable and they bond well with styrene. If the figure were more like Hasbro action figures, injected molded, then acrylic paints would be the best. Itís a bit flexible and will bond ok with the plastic. Now as for chipping, any playing or using the custom with the any paint job, will have natural paint chipping. Even the store bought toys are not immune to chipping. Even though a paint company says their paints bond with plastic, they do not specify what type of plastic their product has been tested for.
I hope this helps,