Maybe you can get some info about what your state requires for educating gifted kids on your state's department of education website. Some states require that a school gives a kid appropriate learning materials even if there is no "official" gifted program in place until later grades. Also, I would ignore the person who discouraged you from looking into the self-contained gifted program and check it out for yourself. You know your kid best.
Also, how does your DS5 (dear son age 5) like kindergarten? If he seems to be liking it well, maybe there's no need to do anything just yet? If he's unhappy and really not learning anything, maybe you could check out the 1st grade, and if it seems a better fit, suggest to the school a mid-year grade skip to 1st?
Also, check out Hoagies gifted. They are full of info on gifted kids. Here's a link to the advocacy page.
http://www.hoagiesgifted.org/advocacy.htm good luck!
