That's a good question. The best thing you can do is check with your current homeowners or car policy provider. Afaik, bundling policies is way easier compared to having separate policies. Don't forget to check with them what their definition of a tiny home is to avoid issues with your coverage.
As the preferred insurer, it really depends on your preference and budget. Some prefer larger companies like State Farm, while others want to get specialty providers or smaller regional insurers. Since they cover tiny homes.