Call the Mental Health Mental Retardation Assn. (MHMRA) for referrals if they do them. Call United Way. Call Houston Child Guidance for referral (excellent source). Just three off the top of my head. This city I know well and it's resources. In fact, start off with Houston Child Guidance and see if they have a therapist who will work with you.
Don't let money be your guide to what is good or not as many therapists do work for clinics (no money to set up a practice for themselves yet), and are excellent.
I know, personally, of some very good work done by practicing therapists with Houston Child Guidance. They were working there until they built enough of a following to go into practice alone (much like hairdressers and other professions do), and did alot of good work.
Good luck!