J.S.
My son has SPD and is sensitive to noise. He can't focus in a noisy environment (like a party) and needs to be able to move around. I had him screened by Action 4 Kids when he was about 3. I called and asked them how the screening works. They got my insurance info (I have Blue Cross of IL) and dealt with calling the insurance co to find out my coverage then worked with me on payments. They are in Naperville and Shorewood: http://www.actionforkids-usa.com/ for the contact info.
Things I have learned:
Read "Raising a Sensory Smart Child", "The out-of-sync child". Use games from "The out of sync child has fun" to help your child get organized when you see her start to lose it. I checked all of these out of the library before I was sure if he actually had SPD.
Teach your child ways to cope. For my son, when we have to go to a place that is chaotic, we warn him ahead of time. We tell him to find a good "centering" spot that he can go to if he starts to feel disorganized (Like the waiting area of a restaurant, the bathroom at Chuck E Cheese, a bedroom at someone's house, under his grandma's dining room table). He carries an MP3 player and plays his own music if he can't find a place to get away physically.
It's all about being sensitive to the child's needs and teaching the child coping mechanisms that are socially acceptable and easy to do.
Also, if you want to go to support group meetings there are a couple of great groups on meetup.com