I would love to hear IEP suggestions. I do plan to get a book on this.
My favorite book on the topic of IEPs for gifted is
Reforming Gifted Education by Karen Rogers. It is also required reading in the Advocacy Guidebook from Davidson. It gets a bit wonky for mere mortals, but you'll likely come out with a better understanding of the options.
And as long as you are in a studious frame of mind, be sure to download and work your way through the
Davidson Advocacy Guidebook. (If you do everything they ask, you are guaranteed to add a few points to your own GAI.)