The second one is useless. The first one is good, but there are better ones. Like previously mentioned, close grip bench press, dips, skull crushers, tricep rope pull downs are all excellent. The tricep consists of 3 heads (outside, middle and inner). Do not worry about the middle head because it gets worked no matter what. Do stuff like extensions or rope pulldowns for the outter, skull crushers / close grip for the inner and dips for both. Don't even bother with kick backs because they are for women. Good luck!