Actually I've done the OPs number two, catch as many as I can. But I haven't raised all of them. I just like catching them to fill my pokedex even though I don't plan on completing it. Number one is probably what I'd prefer, and what I did with Pearl. As of now I have about a team of 5 on my platinum, they are in a 3-4 level range with one another, so pretty solid team.
Yet if I restart platinum I will probably combine one and two. Catch as many pokemon as I can, but raise and keep around four, five at most, on my team. It's difficult choosing who I want sometimes, but it usually comes out good. EV training is another reason why I favor option one. I hate EV training, and am still learning about it, but do it anyways to form my perfect team. Meaning I only train the pokemon that I am 100% sure will be my main players.