Man, you are late to the party. I am surprised nobody mention it, but this service has been already available for free for years:
tradingschools.org
The subscription model wouldn't work by the way, that is why Emmett runs tradingschools on the ads model. Let's say you already have 20-30 reviews with 5 of them fairly profitable. Why would I pay you a monthly fee more than once, when I can just pick out of those 5 one or two signal providers and be done with your service? That is why the ads model is the way to go...