Quetzal
I think that the most appropriate type of person to take on the creationists is a generalist - someone who has a thorough but not specialist understanding of a wide range of scientific fields. The vast majority of creationist "arguments" have been around for many years and the scientific evidence which debunks them is relatively well know outside creationist circles. The difficulty is that such a person would need to have full time sponsorship to remain up to date with scientific advances in the relevent areas, monitor the occassional new creationist assertion and take on the creationists whenever they raise their heads. After all, Ham, Sarfati et al are full time, paid mouthpieces for creationism.