I JUST changed mine this past weekend.
I'd recommend ordering from RockAuto.com, as their prices beat out most local auto parts stores.
I chose to go with Wagner products for the brakes because of the great reviews found on this site. I purchased the Wagner rotors and chose the semi-metallic Wagner Thermo-Quiet pads. Great stopping power!
If you haven't changed your brakes in a while, I would HIGHLY suggest purcahsing new slide pins for the caliper brackets too. I've never seen a Sport Trac or Ranger that didn't have seized up bottom pins. Mine was seized so bad I had to take it to the shop to have it heated up and yanked out. My Ranger use to always have the same problem. Be sure to lube them well, even if you decide not to replace them.
Good luck!