Mazdaspeed did some experimentation with brake ducts in the early 80s. They concluded 3 inch hose was min for brake cooling. Anything less in diameter simply did not pass enough air to be effective.
Adding cooling hoses does usually come with the headache of rubbing on full lock. The temps on hoses are not that important. The rubbing of the tire will wear your hose out first. The more expensive stuff will just last longer.
I highly recommend cooling hoses, one to the center of the brake disc (spend the money for the backing plate), and if you can one to the caliper. The caliper hose only if you are a hardcore track rat and are very hard on your brakes.
I buy my hoses in 30 ft lengths and change them once per year. This is for my race car. During the season I wrap ductape around the sections of the hose that get haggered to make them last for the season.