Given the options of starting in a small firm and going to a large one, versus starting in a large one and staying there, obviously the second option will be more straightforward. Working for a reputable smaller firm isn't a problem - it just means you'll need to adjust to a different style and organisation. Having worked for a small firm started by disgruntled PwC consultants, these things often end up with a very similar culture and procedures to the "parent" despite best intentions to do something very different. As a result, the transition isn't impossible to get accustomed to.
