Hi 4 Paws,
I would highly recommend Kiltix from personal experience.
When we used to live at our old address we were in a high tick area in Sydney. Many years ago I did not use any tick protection, as I thought it was too expensive at the time. I would thoroughly physically examine my dogs - golden retrievers - twice a day for ticks. I would pluck between 3 and 10 ticks off each dog every day. This worked for a couple of years until one of them went down with a paralysis tick. I had pulled ticks the night before and she was showing signs the next day.
I used Kiltix tick collars after this incident and for 2 years of living there, never had to pluck another tick from my dogs.
Definitely works. Have never tried any other brand.