Dealing with these organizations frequently they are all about conformity and the team. So then how do you be part of the team and make yourself standout from the rest of the candidates. A kilt can be a great first impression. It could also tell the panel that you are to much of an individual for there department. As you know form being a volunteer the officer that interviews you has his own set of prejudices. Interviews are supposed to be about equality and finding the best candidate but fire departments dont always work that way. I would think long and hard about this. As for not having a suit. Most fire guys are not suit guys either but they probably came up with one to interview. Good luck