I have a feeling you could post the code on /b/ and find out about some vulnerabilities very quickly.
edit: On a more serious note, I've done some work with Palamida and been quite impressed. They can be pricey though. I know you're not keen to accept monetary donations, but I wonder if getting a reputable company to do it for free would work. I'm sure there's plenty of goodwill toward you in the technical community.
Where/who would you suggest? I'm certainly open to the idea.