For show jumping anybreed can be used but for high cup level the horses have been professinaly breed eg. holsteiner or warmbloods but lots of horses that jump are TB's they are an overall a good non...
the horse chooses you just as much as you choose the horse... and remember your feet shouldn't hang over the stomach of the horse. that means that the horse is too small for you. Also, depending on...
There is no "best" breed of horse. Different horses are good at different things. Quarter horses are best at racing short distances, Thoroughbreds are best at racing longer distances, Arabians are...
There isn't really a best actually. It all depends on what you want your horse to do...jump, race, dressage, ECT. Then the breed made for that sport will end up being the BEST. Here is a chart I made...