Proposal for Joint Venture

I work in the entertainment business producing and organising theatre and concert events. I have a partner and we a have been active in this industry for 10 years in various capacities; coordinating tours, tour managing , running club events, marketing, social media campaigns, production management and more. we are now wanting to run our own events and would like to explore working with an established promoter in co presenting tours and events. We have the skill and know how but we lack relationships with international booking agents l am wanting to find someone who can assist in drafting a proposal letter to send to potential collaborators this proposal would express our objective in wishing to entertain the idea of working with them on some projects and be an introduction for us to schedule a meeting a discuss further.