I have not played NU for a while, but I used to find a weezing/lanturn defensive core to be pretty good.
Also, you will change your mind on teams all the time and get bored of one. I used to come in with your mindset MONTHS ago and still have not gotten to the point where I will breed a team.
I recently made a really good UU team, but because of exams, couldn't play it much. I am breeding on of the pokes now and will hopefully finish the rest of the team if I still like it. The pokemon I based the team around was moved down to RU, so I might make an RU team.
But, my advice is is to build a team around an offensive or defensive core (2 pokes) and go from there covering type weaknesses and gaining coverage. Even more important is to learn about the tier and make sure you check or counter each top threat (top 10-15) at least with 1-2 pokes. Immunities are really good. And decide what kind of team you want that fits your play style. I tend to predict more, so I have a fast and speedy team with 3 u-turn/V-swich users for a ton of switch initiative. If I am down, I can easily come back because of that. In addition, I have 2 all-round bulky pokes (one with status) and a rocks setter.