My daughter is in the same boat. We sat down with the pricinple of her school and had a long talk about what she recommended. Blue Valley Schools offer all day kindergarten (though it is fee based) and with that they are able to move kids around to go work with the special ed teachers (librarian, counselors, computer lab, ect.) or the 1st and 2nd graders for subjects they excel in.
Full day is also used for kids who may need more help and need to take extra time to take it all in.
But, in our children's case it allows the flexibility for the kids to be able to move up when they are ready as opposed to rushing through the day to fit all of the same subjects in with half the time to do it. They also spend more time on music, PE and foreign languages (Spanish and French). It's a full day, but they are going to have to do that in 1st grade anyway. Mine refuses to take naps and goes and goes wanting more and more to do, so I think all day will be great for her!
I'm very excited about her school next year. I hope you are able to keep her excited about learning!
And as for homeschooling - don't do it! It is a huge part of what developes people and you miss everything that most people take for granted as rights of passage. I know, because I missed them all being homeschooled.