Transporting horses is a very hard task. If you are just going to do it once, you can rent a trailer or a truck, but if it is part of your work, you should start thinking about buying any of these means of transport.
There are many classified ads at this site that might help you with your search. They advertise both trucks and trailers. If you are looking for something more specific, you can use the search engine they provide at the web page. It lets you search by brand, by type, by state, or by feature. If you are not really sure about what you need, you can find a dealer that helps you with your purchase. They offer a dealer locator at this website that can help you find the one that is closest to your home. If you own horses, you should visit HorseTrailers-Online.com and find out what they can do to help you transport them.