I really like Eskadon gel tendon boots and Veredus tendon boots. They keep my horses' legs protected when competing in international Grand Prixs and I think they do a great job. They can be a bit pricey but I think protecting the legs is a worth the splurge!
I find equifit wraps to be the best in terms of polos because one side is non slip memory foam and the wraps themselves are much longer than regular ones. In terms of splint boots I don't find much of a difference in terms of support once you pass the 75$ mark