Yes, there are a lot of options when it comes to insurance. You may want to call a company and figure out which plan is best for you. I have used Equisure in the past and have been pleased. Not sure if this is still the case but you may have to be a member of USEF... I also really like Hallmark, they have a great prices and customer service.
Usually when I insure a horse (I only insure my investment horses when they are going to be leased out) I get mortality (should one of them pass on, I don't wnat to be out my investment) and major medical. Usually it's something like you pay $500 and they will pay the rest of a major bill, up to like $7500 or $10000 depending on the plan. I usually do major medical in case a colic surgery is necessary. Chances are if one of my horses is going to need some kind of major lower limb surgery it's not going to be sound enough to sell as a performance horse anyways so I don't worry about anything that's more hten $10000 (I think most colic surgeries are like $7-10000).
The last horse I insured was for $10,000 and I think it was like $700 for the year. Mortality and Major Medical. I sold the horse partway into the year and they prorated the fee and gave me my money back for the days I did not use. I believe most insurance companies work this way.
Anyways, there's a lot that goes into insurance so I'd just give a few a call.