I have tested and worked with many different lead generation (and BPO) companies in various countries. It is tough to give suggestions without knowing more of your service/product, ideal customer type, and sales/enrollment process. I have contacts who could be the right fit but it really depends on what is really the best fit. Centers in the Philippines will be a good at some campaigns, but a center in Mexico or Dominican Republic will be better at others. Especially if you need lead generation and sales (cross sale, etc.).

Let me know if you want to talk further about who might be the right fit.