Where is the best place to buy a spaceman costume for my husband?

My son's first grade cl is inviting parents to come to school to talk about their jobs. In order to make our son proud, my husband and I decided that he should talk about his job as an astronaut. Really, he's a janitor, but we don't want our son to be embarred in front of his friends. Where can we find a costume for my husband to wear? We would like for it to look as realistic as possible, with an air tank and fishbowl mask and everything. We've look in costume stores all across town, but we can't seem to find anything that meets our needs. Do you know where we can find a realistic looking spaceman costume for my husband to wear to our son's clroom?