Welcome. This site has been an incredible support system for me. I have learned a lot here. Buy this book:
Asperger's Syndrome A Guide for Professionals and Parents by Tony Attwood
It will be a huge help for you. The right school is essential. An IEP with a "physical disablity" yes..I know it's hard to believe, but it is considered a physical disability and the ONLY way to get him on an IEP in the United States with the proper treatment. The Dx must come from an MD. Beleive it or not, it could be a regular pediatrician! Does not even have to come from a psychiatrist. ANyway, after the IEP has the correct Dx (must be autistic spectrum disorder) from the MD, then the physcial disability will be written in and the correct treatment will begin in school. Without it, your son will have a lot of trouble in school. Mostly behavioral...they are usually very smart and not a problem with grades in the beginning where academics are concerned. Social skills are a must. With the proper IEP information, your son will also get social skills group in school as well. This is essential. It will teach your son about emotions, how to read others' emotions and how to incorporate playing together with others. (ex. My son has a lot of friends, but will not play with anybody else on the playground, etc., nobody will throw him a ball, he will not join any sports, refuses at times to participate in gym, etc.) Martial arts training is FANTASTIC for these little guys for many, many reasons. Look into that. I highly recommend it.
Anyway, it's a tough battle, but there is a lot of help here at Wrong Planet.
Good luck. Exhilarating and exhasuting at the same time. (I forgot to look what country you are in, but getting the right school treatment plan is essential no matter where you are.)