You might check Jobslinger.com and see if it covers Puerto Rico. The signup is free and it might be a good start for you. I gather that many of the companies that shop the US also shop PR where the clients are there as well.
The problem with telling you who shops whom is that our Independent Contractor Agreements with the companies we shop for prohibit it, so even such notations as you have made are not allowed. And a different MSP shops Shell in the US, so obviously you will need to sign up with a number of companies and look around to see what is available to you.