Sorry it's been so long since my children left school, that I have forgotten what age year 8 covers.
I do have experience of removing three children from school when they were aged 13, 11 and 8. I'm guessing one of those ages would cover it. 
When they left school, we'd been told that our then 13 year old might achieve Drade Ds at GCSEs, if he tried hard to overcome his dylslexia.
He's at University reading Psychology now.
Our Dd1 was also trailing badly in the lower sets, she also thrived, and has gotten her uni place too.
The youngest was so severely dyslexic, she had no word attack skills at when she left school and was completely unable to spell even her own name. We'd been told she would probably never read properly or be able to be completly independant. She has just achieved straight Distinctions for her Nat BTec in Music.
All three went back to FE college and fitted in really well socially and academically and far from being a home ed freak, have social lives that are the envy of their school peers and cousins.
We know literally hundreds of home ed teens and all are doing well, at College, in work or at Uni.
I have known a handful of families personally whose children have returned into the system at secondary age, with great success, but most do stay out for good.
I'm really enjoying hearing about the latest crop of autonomous home ed teens, getting their University offers and how well the ones who are already there are doing.
I'd suggest you and your hubby reading around the subject. There are threads here about books on home ed and websites about home ed.
Also go along to local home ed groups and chat to home educators. Almost with exception, they would be happy to meet you and their children will be lovely. If you can talk to their older children, I'm willing to bet they will impress.
There's also a thread here about finding local home educators.
I'll be around later if you have more questions.