While this is not a direct answer to your question, it is an indirect one. Getting the answer from a professional need not be costly.
Many dental professionals will probably see you for a consultation. Sometimes walk-in clinics will see you and sometimes you can make an appointment.
While I haven't tried it, I'm reasonably sure that such a question will be answered without charge by a dentist or a dental hygienist. I've had free consultations and second opinions.
Many hospitals have dental aid available. Stopping in to get such preventative information is part of wellness regime that no health care unit could refuse. They probably have samples to give away.
Every dental care unit I have ever visited has bags and boxes of samples donated by manufacturers to give away. They are not for resale. A dentist or dental hygienist will probably give you a small bag of different brushes, floss, and scrapers to find one that suits your regime and mouth.
Contact product manufacturers directly and ask for samples. They will probably fall all over themselves to please such an aware and cautious person. Their names and addresses are on the packaging in a well-stocked pharmacy or on the Internet.