Hi and welcome,
I have a child that is 2-E - High IQ and profoundly dyslexic. We struggle with how to provide him the remediation he needs and at the same time grow his gifts and challenge him. I'm not sure if we have made the right choice, but we enrolled him in an LD school in grade 3, and have found that the school has been able to place him with other complex and very bright learners that share a similar profile.
I am not sure if the school the district is offering you would do this, but if so, it could be a great opportunity for him to build his skills in areas of weakness, and still be academically challenges. I would do some real digging to find out how they group students, what they use for curriculum and what kind of instruction and or behavioral methods they use to address areas of need.
You may want to try this forum to get more info about ASD, testing, IEP, remediation, etc
http://millermom.proboards.com/index.cgi