Lots of good advice above! We have gone back and forth between virtual school and homeschool. Homeschool definitely gives you the most flexibility and lets you do more in-depth work. We did a research project on comparative revolutions (French, Russian, and American) in 6th grade, for instance. Not something you'd normally see in an elementary curriculum! :-) Both of my dc's also have serious, multiple extracurrics, and pure homeschooling is the most flexible (although virtual school nearly so).
There are three potential downsides, I found, to "pure" homeschooling. (I consider virtual school, at least at our school, which is private, to be a form of homeschooling, since we have a lot of choice about curriculum (we're at the HS level and in a school that tailors curriculum within any given course).) One is that coming up with the curriculum, while exciting, is wearing and stressful and can be expensive. We paid for so many things that flunked out quickly. My fault, certainly. Another downside is that, depending on what your dc's ambitions are, you need to keep an eye on credentialing. WE knew that we were working well above grade level, etc., but no one will credit "Mommy grades," so I found we had to do more standardized testing, CTY courses, etc. We still do a fair amount of this, but the virtual school grades are quite real and provide credentials (as well as helping pacify relatives, neighbors, etc. who insist that homeschooling surely is shortchanging the kids). Credentialing is not just the shallow aspect (getting Grandma to be quiet about how all five of her kids did just fine in public school etc. etc.) but also the internal sense, for the child, of how he/she stacks up in the eyes of a third party.
Third is the perfectionism issue. Pure homeschool avoided the perfectionism for us, but confronting it in virtual school was better for my dc. What I mean is that DC initially felt very pressured about having real grades and a real schedule and having other people read the writing, etc. But going through that and getting past it was an important educational task that I couldn't accomplish in pure homeschooling, by definition.
Concretely, and more positively: pure homeschool is definitely doable, and it makes for a fun and flexible family project! I strongly recommend Singapore Math. We tried lots of homeschool options (and spent way too much money! :-)) on others. SM is high-level, not too repetitive, and well-structured. I'd get the optional problems books as well. Of course, all this depends on your dc's tastes.
English is a hard one. It happens to be one of my strong suits, so I always had fun choosing novels, poetry, etc. I did look around for courses and didn't love them. You might ask on the Well-Trained Mind boards. You could always do an anthology (like the Norton anthologies for high-school students; I'm not sure what level your dc needs).
Foreign language is another hard one if you don't speak the language, but that's true in virtual school too.
