There's a lot of not so great posers out there, ready to leverage your lack of know how. Network with your peers and get referrals from people you trust.
And I'm not sure what a "good" resume would look like for this case. My opinion is that resumes, for consultants, are generally a bad sign. I don't have one and won't, people find me. And if I were looking, I wouldn't send out resumes. That's a generalization of course, but I'd say their website, and then references, dwarf whatever you might find on their resume, if they even have one.
Personally, if I were in your shoes and asked for a resume from a ppc consultant and he/she/they said they didn't have one, I'd say "good, what's next?" and then I'd dearly hope the prospective consultant would ask you about your goals, to see what your current setup level is, whether you have an aff program that permits ppc, who currently handles your ppc, what engines they use and which ones they want managed, what's not right about it that you want to change and so forth... point being, the consultant should be asking the right questions quickly to determine for themselves if they are a good fit.
Probe your peers. Ask around at conferences. Someone you already know, knows somebody who would fit, they just don't know you're looking.
Try LinkedIn too, it's a good networking tool for this purpose, where you can see who is tied to the people of interest.