Not sure who you can speak to that will help you with that, but I am with you on this.
Here is an example of a ceremony on the RDF website for Luke William Ashton.
Arthur C. Clarke who sadly died last month said this with regards his funeral arrangements -
Absolutely no religious rites of any kind, relating to any religious faith, should be associated with my funeral.
I think you can put something together in your will? This
website says "the funeral director takes care of the practical arrangements, but it is up to you to say what kind of funeral ceremony you want" (It is a UK website but I am sure the same applies here). I am going to put something together in my will, I guess it will have to be up to my remaining family to decide who does what on the day - if they do anything that is!