I know a couple of people that train Uechi Ryu and it sounds like fairly intense training which included putting their big toe through a wooden board.
I do not know much about the different styles of Karate, I trained Karate (Villari) once, for one whole month about 25 years ago (
and decided to stay with my TDK school) but that is really the extent of my experience with it.
But if you go here
http://www.answers.com/topic/karate and scroll down to styles it lists a few and some have descriptions
Styles
Wado-ryu ("way of harmony"),
Wado-kai ("school of peace"),
Shobayashi,
Koei-Kan,
Kobayashi-ryu,
Washinkai ("Way of Harmony of heart, mind, body and truth)
Matsubayashi-ryu,
Matsumura Seito,
Matsumura Motobu,
Chito-ryu,
Shindo Jinen Ryu,
Shorinjiryu,
Shorei-ryu,
Shotokan,
Shotokai,
Shukokai ("Way for all"),
Goju-ryu ("hard-soft way"),
Kyokushin ("ultimate truth"),
Ashihara, named after its founder,
Kansuiryu.
Uechi Ryu,
Shito-ryu,
Shudokan,
Bushido Goju-Ryu,
Genseiryu
Isshin-ryu. Some organizations offer hybrids of karate styles such as the JIKC.
Traditional styles - because they were founded during the early part of the 20th century.
Shotokan,
Goju-ryu,
Wado-ryu,
Shito-ryu,
Kushin-ryu,
Shindo Jinen Ryu