Would he have any peers at the Catholic school? I think that's so important, and has been a real challenge for my kids, especially my introvert. If I were you, I would send your son where you think his needs will be met and where he'll have the most chance for finding kids like him.
I have three kids, including twins, in three different schools. We tried having the twins in the same school, but it was a terrible fit for one of them. The friend issue is just one factor, and we feel so strongly that the new school will be a better social fit for him that we're willing to drive quite a ways to get him to that school.
So we do a lot of driving. It isn't my favorite thing, but my kids' needs are so different from each other, we don't feel we have much choice.
