D.B.
I would get the recommendations and info from the former teacher and speech/OT people (I know they're on vacation, but you must have something in writing about your son's learning issues, social weaknesses, reading difficulties...everything). Then I would talk to the special ed people in the new school and work out a plan.
If you aren't sure what a successful teaching strategy would be for your son and/or if you don't have teaching experience, I wouldn't suggest that you implement a new regimen at all, lest it confuse him. Adding stress is the worst way to start out next year.
Instead, visit the library and check out some books, and just read to him - with joy and relaxation, not with any effort to get him to pronounce words. Get books on a topic that interests him, rather than an instructional guide to the ABCs. Visit the zoo or the children's museum, and get him to "help" you read the signs at the exhibits that intrigue him. Wait for him to ask you a question, and then say, "I don't know. Let's read this description to find out."
Play board games that have a limited amount of reading, and occasionally say, "I can't see what it says on this card. Can you help me?" But ONLY OCCASIONALLY.
From my experience in 2 schools, most of the kids who repeated kindergarten just blossomed and made great strides the following year.
And by the way, my son was 6 when he started kindergarten, so your child won't be the oldest or sticking out like a sore thumb.