You always want locking tuners, so if the choice is between those two, get the Sperzel parts. But, Schaller also makes a tuner called a "mini-locker"...
They work the same way the Sperzels do, but the knurled nut on the back used to lock the string in the post is a bit thicker so you can get a better grip on it. Other differences to consider are the Schaller parts have a brilliant finish, while the Sperzels are a satin finish. The Sperzel parts probably weigh a few grams less. The Sperzels have a locating pin for anti-rotation you need to place, while the Schallers use a screw, which is easier to place. They're both premium tuners so you can't go wrong.