Westmark's rhymes with:
hartmarx, benchmark's, benchmarks, birthmarks, bismarck's, caremark's, cellmark's, denmark's, deutschemark's, deutschemarks, earmarks, hallmark's, hallmarks, hartmarx, landmark's, landmarks, pathmark's, raymark's, southmark's, trademarks, watermarks
Westmark's sounds like:
westamerica, westamerica's, westmarc, westmark