Well, first things first, providing your child with what they need is a marathon, it's not a sprint. Pace yourself. You don't have to, nor likely should you, start out with a master plan, rather, take it one step at a time, see if that step works / pans out, or if you're going to need change direction.
Probably the first step is to familiarize yourselves with how "The system" at the school works. Each school district and sometimes even schools within the same district have quite different systems for serving GT children as well as requirements to be in their GT program if they have one. Once you're familiar with how the schools system works, that might answer your question about sharing text information. Sharing that information might be a good next step, on the other hand depending on the system it might mean little or nothing to them depending on how their system works.
Once you understand the school's system, inquiry about who might be the best teacher for your child is a good next step. If the school understands that your child has some specific needs they're often willing to assign the best teacher for the job. Once that's accomplished, an e-mail introducing yourself to that teacher and some honest background and commentary about your child so that teacher has a starting place to work with your child is a good idea.
Any other advice I might be able to contribute would greatly depend on what information is gathered and what transpires from the efforts I've already described. Again, take it once step at a time, adjust, modify, and be prepared to seek sources and opportunities outside of the public school system. Chances are, no matter what school your child goes to, it won't be enough to fully help them to their potential.
