What do you actually mean when you talk about crypto accredited portals, are you not referring to ICO or STO , STO are very much regulated by the government and they are investment platforms where investors can invest money into a project in order to make profit in return in few months or even years, one of the popular company that carried out an STO recently is binance exchange which is the most popular crypto exchange in the world.

I don't understand the part you are talking about down payment, maybe you can throw more light on what exactly you are looking for.