If you're renting gear from a rental house and also need property damage insurance, you're best to use one of the major film insurers. CHUBB is one such company, and they have short shoot and low budget packages. You typically don't deal with the insurers directly, you normally use a broker who shops your project around to get the best price.
Wouldn't big film insurers be more geared towards big budgets?
I recently finished a short and the big bonus was that I didn't have rent since I used all my own equipment. So all I bought was the accidental injury package. But yes, you should have insurance.
Take a look at Athos ( I dealt with them and they answered every one of my questions (and I had a LOT, since I'd never bought production insurance before.) It wound up being very reasonable.