It sounds like you are seeking capital (as you state that you will need at least $25M) or seeking advice on who to talk with in order to raise capital.

I think that this will be a relatively hard venture to raise capital for. In that range - and given that it is non-tech probably you should talk to private equity funds with experience in related fields.

My guess is you will have a hard time to get equity or debt financing without collateral for that amount starting from standing still. Unless you have a history of success or a rich uncle.

There are many different funding sources (government, private angels, VC's, banks, crowdfunding) - there may be very few are available for something like you initially describe.

Capital intensive - and also a service business.