Need Intellectual Property Ownership contract

Hi, We have employed a number of freelancers to develop a few products for us, and we would like to have the legal assurance that we will have the ownership of the product for sales and distribution purposes. We are based in the UK, but the freelancers are based around the world: middle east and eastern Europe. Therefore we require a intellectual property ownership agreement to be written. Please note that our maximum budget for this project is $50.