I've been homeschooling my ds7 this year for 1st. Previously he had been in two different gifted schools (one structured and traditional/ the other Montesorri-type and unstructured/untraditional), but neither could accommodate ds. My son is like your son - very much an autodidact who prefers to self-direct, self-motivate with his learning. He's spent days just reading one book/subject after another. I'm waiting for another set of WJ-III test scores for DYS.
By all means if you have a school that is willing to do independent projects or accommodate your ds, then try it. Otherwise, there are many variables at hand from the curriculum and the way instruction is delivered or presented to other kids and social/emotional issues like bullying.
There are many ways to homeschool a child today; we loosely followed a general curriculum series for grades 1-6 this year for a bunch a reasons (including a portfolio/work samples for DYS), but next year I'm taking another tack. The world is your oyster. I think two of the most helpful books that I recently have read provide a good starting point.
1. Rebecca Rupp, Home Learning Year by Year (needs to be updated, but a wealth of resources and a basic guide on what usually gets taught in public schools from K-12 for each year). You'll find that the 1st grade+ curriculum is rather basic and quite lacking for your son unless a school makes accommodation.
2. Kio Stark, Don't Go Back to School. It's a collection of interviews on how people learn traditionally or untraditionally through school or not, but the resources and ways people approach subjects/work are helpful.
