Umbrella Insurance Policy?

[Russ DeWolfe]

Hi! We have 9 rental properties in the Dallas Texas area. And are thinking about getting an umbrella policy on top of our insurance. Do you find that this is a good idea and if so what is a good company to use?
Also one of our houses is a trailer and the insurance I have been quoted is about 4 times more than our other houses. Is there a company out there who insures trailers at a reasonable price?
I was wondering if anyone had any insight into these two questions.
Thank you!