Meh, I used Ultra Balls most of the time. :/
And I'm currently trying to build up my competitive team, but I need a better way to train than doing wild pokemons. I've caught every legendary except the roaming one in Black.
You can catch both of their eveo's later, it might be nice to keep the dog around for cut, and when cut stops being important just store him. I trained the bird, even though I didn't need to. The first pokemon worth training is that gothic one, you'll find it on route 16.