Most every company out there can manage this, but we use Farm Bureau. Toole Insurance is who we use when we travel overseas or do a special gig, and they specialize in technical. They also have copyright violation insurance.
I think that this is the company I'll be switching to. Right now I'm paying $400 yr. for $50K (their smallest available) I'd feel comfortable enough with $20K coverage (not counting liability):
National Association of Mobile Entertainers offers
$161 year for $5 K and $240 year for 20 K
contact: Bruce Keslar at 1-800-434-8274
Randy