We were very reluctant to homeschool our highly extroverted DD for the same social reasons, but it worked out pretty well. She found having her educational needs met to be a higher priority than having her social needs met... though we were able to help with some of that when we hooked up with another homeschooling mom down the street for daily "recess" together.
This year (her first following the grade skip) DD is being appropriately challenged for part of her school day, and is enjoying the social benefits of school as well... but she's still saying that, all in all, she'd prefer to be homeschooled again.
As far as outsourcing that, that's not something we had to worry about, but assuming the price is right, obviously finding the right homeschool tutor presents a major challenge.
