We use Angelyn's step in harness too and I love it. I have a lot of different ones..but now I just mainly use her step-in one. Also you can get the backing with satin which is nice/helpful with the coat.My favorite "everyday" harnesses are the step-in harnesses from Angelyn at Tickled Pink Boutique (http://www.shoptickledpinkboutique.com). They are extremely high quality and are easy to put on/take off when you have a squirmy dog! They are adjustable, and she will also custom make you one if you prefer a certain ribbon/webbing color. You can "upgrade" them with a metal buckle and/or an additional D-ring in the front if you prefer.
Some of the vest-style harnesses you see are great, but for a growing puppy I would probably wait to purchase one because they are not as adjustable. Your puppy may have a 9" chest now, but by the time he's done growing his chest could be 13"-15" so you would have to purchase several sizes between now and then.