Hi! First of all, God bless you for all that you are doing for your boys.
I'm familiar with ADHD, autism, and ODD, but not the other two by their acronyms. If the boys have official diagnoses from a doctor or psychiatrist, you should have a few speed bumps but not impossible hurdles to get the help that should be available in the school system to help. Your pediatrician should be able to provide great resources for information about each diagnosis.
Have you met with the principal and/or your boys' teachers? If not, it would be a very good idea to do that with and/or without the boys. That way, they can begin to assess their skill levels and possible areas for more assistance. Again, depending on the school system you may or may not need to be more proactive and push for either a 504 agreement or an Individualized Education Plan (IEP), if you and the school system believe that such assistance is necessary.
The process to attain special education services can be a very tricky, legally binding process. If specific interventions by the teacher are required on a regular basis without the need of a special education teacher, then a 504 should offer enough protection. If another specialist (speech, special ed, emotional support) is necessary, you will need an IEP. The school district where I worked had a school-based intervention teacher who would help parents take the next steps toward whatever assistance is necessary. A guidance counselor could also provide insight as to what comes next in the process. You need someone at the school who works to understand your son's needs and who works for his success as hard as you are working for it, no matter what steps may need to be taken to get that help. The IEP process can be very time consuming, often taking up to a year in the upper grades. Kindergarten is a great age to get early intervention assistance. Don't be intimidated by all of this, please. Just take every day one step at a time as it will be a learning process on both sides - for the school to learn about your son's needs and for you to learn how the school can best help him and you.
UNfortunately, I don't know much about the preschool assistance programs, but this info should help a little for the kindergartener. Sorry! Best wishes for all of you!!!!!