Really, start in the library. No joke. Let him pick something to read and then write about. Just ask him broad questions about what the book was about and what he thought of it and why. Consider it a pre-test so you can see what he can do if he's interested in the topic.
The nice thing about reading and writing is that if you have a book and a piece of paper, you're in business. No, it may not be a highly organized teaching time. But with a book to read and write about, you can work on brainstorming, revision, basic grammar and sentence structure, etc. in a laidback fashion.
Besides, if you were going to deschool for a while, you're not out any time, right? Why not let him lead you? See what he can do.
But I should warn you, I'm not a big fan of pre-packaged curricula.
I find that they tend to be ill-fitting for my son. Some are better than others, of course. But unless they're pretty cheap, they rarely seem worth the cost. We tend to be curriculum rebels a bit. We just use books like "What Your Xth Grader Needs to Know" and the World Book site:
http://www.worldbook.com/wb/Students?curriculum . These help me to make sure he's not missing anything major. That's rarely a problem so far, though.
I do buy a lot of workbooks and manipulatives at end-of-season sales. I can't pass up stuff that's 75%-90% off, you know? If I never use them, I can certainly resell them for what I paid for them, so I won't be out anything, and that way I have a wide variety of materials on hand depending upon what appeals to him. Those will be coming up in May, and I'll be sure to post what I find. Others share that stuff, too, happily.
So, yeah, ours is a laidback, eclectic approach that would make some people nuts, but it works for us. Certainly starting there might buy you some time while you look for something more formal...
