Inflatable rental companies will need several types of insurance to provide the correct coverages.
General Liability
This coverage will provide defense coverage for bodily injury or property damange for your negligence. This will be a requirement from all parks. Limits required are usually $1,000,000 per occurence / $2,000,000 aggregate.
Commercial Auto
Your personal auto policy has an exclusion for business use so you will have no coverage under your current auto insurance policy. A commercial auto policy will cover you for both business use and personal use. If you use a trailer to carry your rentals to the location add this unto your policy.
Inland Marine
This coverage will provide protection for fire , theft, and vandalism for your inventory. If you cannot afford to lose your inventory to theft or fire, this is an important coverage to purchase.
Workers Compensation
This coverage is a requirement in most states if you have employees. It provides coverage for bodily injury, medical bills, loss of income, death for all employees, full time or part time.