Oh, I don't know that I'll be helpful to you that way. I bought no official curriculum, just random odds and ends. I liked a good chunk of the science (nonfiction), history (nonfiction) and historical fiction they offered (grades 3-7, generally), plus I bought a lot of math workbooks.
I find that having lots of workbooks around that I buy for $1 or $2 works better for me than plunking down $100 (or whatever) on one set thing. (That he then outstrips in a matter of days!) If we use up a $1 workbook in a day, I don't feel so bad about it!
But if coverage worries you, this probably won't be an approach that will make you feel better. It's a pretty random way to go at it. It works likea charm for us, but I suspect it would make you nervous...unless I've persuaded you that coverage happens without your really having to work at it too hard.
I generally like having plenty of options around for DS7 to choose from. Since we're very child-led, I get lots of things that seem too hard for him and then just have them around. When he picks them up and gets interested in them, I know he's probably ready to advance faster than I'm going.
My priciest purchase was probably buying several of the practice tests at more than one grade level (5th & 6th, I know I bought). I think it will be nice to have them to see if DS7 is really ready for above-level testing next year, and at what level.
Now, the practice tests you might want to get! They were pretty cheap! $5 for the child's test and $2 for the teacher's manual, if memory serves. And grades 2-6 were all available, as I recall, if you weren't picky about which state's test you used. That might help soothe your mind about coverage for a lot less than an official test.
Dunno if this helps at all...
I barely made the free s&h requirement.