Traffic Vance pretty much has the best traffic, across most verticles, including debt relief. But you're definitely fighting an uphill battle if you're coming into the mix fresh, especially if you're competing against people who're selling leads directly. If they're selling leads to an end buyer for $25 apiece and you're getting an $8 payout from a CPA network, it's hard for you to compete.
All that said, there's still a lot of $ to be made. Experiment with building your own list and stringing offers together, instead of just doing a straight LP or direct link.