Help with sponsorship letter / program

I am seeking help creating a sponsorship letter and program to help with a unique project I am working on. I am a professional dog trainer based out of Las Vegas/Los Angeles and relocating to Alaska to train to be a musher in the Iditarod race. I am looking to put together an introduction letter and sponsor/donation packet & program for both my existing clients who already support me as well as others who may be interested. Will want to create a Patreon (or other) incentive-based presentation so it encourages people to support me on a regular basis and offers them something in return. Ideally would like to work with someone who has experience in this and can take the lead to help accomplish this project.