I can't think of anyone here who has their child on 4 different medications. Honestly it screams as an act of despiration on your part to do that too your child. I know you want what is best for him, but I doubt you are going to find that in the bottom of a bottle of pills. The very fact you are posting about it suggests that it is not working as well as you would like.
I think you need to get the drugs down to one or two that work for him, and look at environmental changes to accomidate his needs. Your child has a neurological problem, his brain is wired differently, this is not a strict behaivor problem, or something you are likely to fix with medications only.
I personally believe that medications can be a great help, or one of the most distructive things to a child. I had my son on a Ritalin and Clonodine mix for nearly a year when he was 8. The ritalin was for "adhd" but it made his tics (now I know stimming too) much much much worse. We thought he had tourettes. The clonodine was to control the tics and calm him down. Give the wrong med at the wrong time, and you had major problems. One day I gave him Clonodine instead of ritalin, he was back in bed before he got to school! Clonodine was also dangerous, overdose or underdose could result in a stroke! At the end of the year, it became very evident that he was not learning anything on the drugs, felt like crap and it was not in his best interests to stay on them. His acedemic performance was worse, and his behavior was worse then when we started over 9 months prior. The fight at school got so bad I had to homeschool him for 4 years. He has since returned to school, and is now taking Strattera with much better results. He still has poor concentration, but it is a "little" improved, he is more mellow, and not as anxious. Best of all, he reports no real side effects and WANTS to take it for the benifits.
I wonder, what "ocd" traits does he have? Are you sure it is not mostly stimming?
I also wonder if the fits you mention are not meltdowns due to being in the wrong sort of environment or doing things he is not comfortable with. It may just be when he is on the drugs, he is turns into a bit of a zombie, and can't really "react" the same way. However, it does not mean that he is not feeling the same level of frustration inside.
I really think that you need to take some time and reevaluate what is going on with him. It is obvious you care a great deal for him and want what is best, the parents here have tons of great advice if you are willing to listen!