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.
I'm pretty up on treatments for my daughter. I've been to homeschool groups, special ed groups, etc and a private evaluations done by a neuropsychologist and a learning specialist.
Thank God for the internet. I get lots of supplemental worksheets and things to help her from the homeschool groups. We do a lot at home, especially in the summer.
She has brain damage, and she is very different than a lot of other kids. She has little short-term memory, but above average long-term memory. She can't hear the difference in sounds well, and she can't pronounce things clearly.
She's a lot like an adult whose had a stroke, and in fact that is where I get a lot of information about her.
She's doing okay. She's at grade level for reading/writing/spelling, but she will probably never be a great reader/writer. I think she will always struggle (and the research backs this up).
We're just lucky that she is great at math (95%).