I would interview with the two and see who you prefer, who "feels" better to work with. Ask them about their degrees, etc. Schooling is not all that important to me, yes a psychologist goes to school longer and studies psychology rather than social work/sociology but it is probably more important how long they have been in practice, how well you and they communicate with one another, etc. An MSW can certainly be equally as effective as a therapist (or there would not be such?) and it is possible they may be less expensive too, if money is an important consideration to you.

Check your state laws about licenses to practice, etc. and see what it takes to be a "therapist" in your state. Education is more about "what" is studied, what direction therapy might be approached from rather than how good a therapist one is.