Like St. Pauli Girl, I'm just a parent, but I wonder if Susan Winebrenner's book, "Teaching Gifted Kids in the Regular Classroom" might be useful.
I used to be an elementary teacher, now Homeschooling, but I recently got to look at this book and it looked quite good and applicable. If you are doing things aimed at gifted children like that, it is quite likely you will become a go to person for ideas if anyone is stuck. I think it would be worth getting hold of that book.
As to specific ideas, I would personally be looking at either projects negotiated with the students or short term extensions. Short term (one-off) extension units are likely to be easier to sell to staff. Student negotiated projects are going to be less work for you.
If you want some specific program suggestions, you might want to post the subject, someone might have some good resources.
