My son was on Ritalin SR for a couple of years (until it became difficult to refill due to stock issues, then we switched him to Concerta). Ritalin SR is rated to work for something like 7-8 hours, so that might be perfect for you. I believe Adderall is one of those really long-acting ones, which explains why you're having sleep issues, especially if you take it later in the AM. I think it can be in a person's system for about 13 hours.