I have a daughter with speech problems. She actually reads better than she can speak. Decoding helps her with the speech aspect and reading.
Her decoding is still low, and she is in an multi-sensory reading phonics based reading program this year to help her improve her decoding skills. She can memorize words easily, but without the decoding she won't be able to move to that next level.
Of course, the public school would not provide the reading program, and we switched her to a private school that would. We looked into homeschool, and hiring a tutor. However, tutors are very expensive ($50-$100/hr) and it seemed like a better bang for the buck to invest in the private school ($7500/yr). (
The training for the multi-sensory reading program is very intensive, and is very costly. That didn't make sense either since I would only be doing it for 1 child.
I don't have any experience with the sort of problem you describe. There are homeschool groups focused on children with learning problems. Even though you may not want to HS, it might be helpful to talk to some of those parents in your area if for no other reason than to see if they have any useful ideas.
On a lighter note, I was convinced my 9 year-old had a speech impediment because he was always mixing up "THs" and "Ss". In fact, I was convinced that I was going to have to learn to do the necessary therapy myself or hire someone. One day I saw a link to this video: http://www.youtube.com/watch?v=FrYRY6kx550 . After I watched it, a light went on. My sons speak fluent German and the 9 year-old is kinda-sorta tone deaf (normal hearing, but he won't be singing professionally anytime soon). I had him watch the video, which he found hilarious, and he was instantly cured. I think he could actually tell that he was mixing up the sounds, but didn't care enough, or was too lazy, to fix it. The humor did the trick - the "speech therapy" was 100% effective, required 40 seconds, and was free.