It's really great that they've been so supportive at the school. By looking at your signature you might want to consider requesting that they test for Physical and Occupational therapy as well.
PT for the awkward gate (does he "toe walk"?) and Occupational Therapist (OT) for the fine and gross motor skills.
Don't sign the IEP right then and there unless you feel that they've given you everything that you need for him. You can always ask to take it home to digest and understand everything, sign it and bring it back. If there are corrections or additions, you can note them and discuss with them. Sometimes you can call the School psychiatric. and ask for a copy prior to the meeting so you can bone-up on terminology.
Ask as many questions that you may have. Be sure that they understand that a lot of his behavioral issues are based on sensory integration issues rather than conduct based.
If he's acting up in class or at school request a Functional Behavior Analysis and a Behavior Intervention Plan. (FBA and BIP). These will allow the sensory problems to be considered by the teachers/paras/administration.
Go and feel comfortable and confident. Question, question, question.
Talk to any outside counselors that you're working with and see if they have anything that they think needs to be considered and bring those concerns with you as well.
Most important: don't be intimidated by this. You're going as an advocate for your child. You're a strong person that's looking for him to have a great education. He's just wired a little differently so he needs some accomodations.
http://www.bridges4kids.org/IEP/iep.goal.bank.pdf
JJJ posted this on another thread and it gives ideas.
Let us know how it goes!
Beth