I would contact the DoDDs elementary school directly. Based on my experience, they may want to do an assessment of your child to determine eligibility and once determined to be eligible, do an IEP. The first POC would be Ms. Young, I believe. She did our son's assessment/testing and was great - a very nice lady! She will get you started/pointed in the right direction.
Not knowing the age of your child, I will say that there are eligibility issues surrounding the school a child attends. If they are school age (K-12) in an area, like ours, that offers a DoDDs facility, they are ineligible to recieve educational services if they attend a different school (e.g. Montessori). My son is able to receive services because he is still in pre-school and DoDDs does not have a pre-school program. He becomes ineligible at the end of this school year as we have no plans to transfer him to DoDDs in the fall of 2011, when he is scheduled to start Kindergarten. His speech therapist is aware and is working with him to ensure that he is ready.
We talked about speech therapy outside the school, but there are a couple of problems. 1. The DoDDs folks are not allowed to 'free lance', as it were. 2. An Italian therapist would be ineffective, because they wouldn't be able to teach our child the required sounds, etc, that he needs to know for English as a first language. We have sounds that Italians don't use and vice versa.
One concern to sending your child with speech apraxia to a school other than DoDDs - many of them have a large number of non-English speaking children. For instance, the Montessori and International schools at NATO have a high number of local Italian children. The NATO and American students are greatly outnumbered. While English is spoken as the teaching language, it isn't the language the kids generally use to communicate with each other. This type of environment may be difficult for your child. My son has only attended Italian schools, even before we knew he had a problem, so he is comfortable in a multi-lingual environment. Just a thought.
I hope this information is helpful!