I have a Yepp Mini front-mounted child seat (purchased at REI) for my Breezer Uptown 8. It was easy to install and has a quick release so that I can remove it when I ride to work. There is a lock on it to prevent theft.

I enjoy having my child in front of me. We can easily communicate, and I can see when he's leaning or falling asleep.

The only issue I have with the Yepp is that my knees hit the child seat-- I have to pedal in a slightly awkward knees-out motion. However, for my needs, it's fine. (If I were commuting or doing longer distances with him, then I'd work on adjusting my saddle, etc., in order to find a better pedal motion.)

One caution: I don't know if the Yepp Mini bracket would work on wide headset stems. It fits perfectly on the Breezer, but many headset stems are a lot wider in diameter.