My wife and I used Jason Wagner (see his add in the Gringo Gazette. He is a broker (out of San Diego) that deals with American insurance companies that insure homes in Mexico. I believe we are with ING this year..
Yes, Chubb historically has been excellent. Don't know anything about the availability or pricing structure in Baja, but they have a good rep for fairness.
They offer a custom home package in the US. My former boss's 8000 sq ft, custom designed home burned down near Reno. He had purchased Chubb's comprehensive coverage approximately 6 months before the fire (don't know the exact product name) , and they handled the loss very well. It didn't hurt that he told them that he would NOT hire an independent adjuster if they treated him fairly. He never had to make the call. True story.
Ask for EQ as well. I believe it's not TOO expensive.