Public school is still requried to offer him a program, even if you decide to go to private school. It is going to be difficult for him to get what he needs in catholic school, they ususlly just do not have the resources and support services to make kids with special needs successful. He may qualify for speech and langague even if he is not attending public school. It is an instructional service, so they may still have to provide that. The one exception my be if his issue is only a cognitive one, and if he will learn how other children learn, only slower and with more repetition. He might do OK in catholic schools under these circumstances with private support services. If he is high functioning, or has peeks and valleys in his intelectual functioning, a langague based issue, or fine motor needs, he will be better served in public kindergarten. He can't fail public kindergarten if he has an IEP, under no circumstances should you hold him back as this is not an effective educational strategy for children with special needs. If what the teacher did the year before did not work, he should not give it another go, that is not his failur, it is the schools and in public school, he would be due compensatory serivices to bring him up to grade level because the school failed him. Many parents bail out the school by allowing rentention which is not good for children (especially ours.)
I would go ahead and see what the public school will offer, and compare the two programs and see which one is going to be best for him. We had to give up on our committment to catholic education. What we found early on is that they tried very hard to help, but just could not offer us what she needed. At one school, we were asked to hire a full time aid and pay for it ourselves, above the cost of the tuition. It was just not fesable. Once we were in public school and she was progressing, going back is not an option either, as most of the cathlolic schools in later grades are looking for "average to above average students" not above average needs. Unless you have a very progressive parrish school who has a large committment to kids with issues, you are probably better off in public school and CCD.
If reading is going to be an issue, you want him to have an alphabet phonics program, orton gillingham based, sometimes called dyslexia instructional or intervention programs, because all children can learn to read this way; he need not have dyslexia to need this method to learn to read. You will want to avoid whole language programs and reading fluency programs which will not help him learn to decode. These programs are available at public schools, and if you advocate, you can get them. You need to be able to demonstrate that he needs this, and the earlier you do, the better off he will be. If you stay with catholic school, you may be paying for this kind of reading isntruction privately, and it is best offered as an intensive program, with daily instruction so private serivice is expensive. One think is for sure, if he stays in catholic school, and he is not progressing with reading from the outset, assume that this is what he needs and get it for him sooner rather than later. Learning to read is essential, and it has an experation date! The best window for learning to decode is prior to the end of third grade. Most kids will need this program for one or two years and will make significant progress in the program, if done prior to the end of 3rd grade.
Martha