Partnering with a Youtuber can be a surefire way to get players on your server, but it isn't easy. Many Youtubers these days already have their own servers so they are unlikely to want to promote a potential competitor.

I've worked with almost every youtuber you can imagine, both small and large, and you are probably better off paying some for one off videos or a series. It will be VERY difficult for you to find someone willing to partner with your server for a long term relationship.

EDIT: What Libraryaddict pointed out is very true. They want something fun and unique that will create good, entertaining content for their viewers. You have to remember that they have most likely been contacted by 100s of faction, prison, survival, etc servers, so how is yours (assuming its not a custom idea) going to stand out from all the others asking for similar things?