YOu won't go wrong with a Burley or a Trek for that matter. I might offer some advice here however. I bought our trailer about 3 summers ago. I did all the research and was about ready to spring for a better trailer and then the voice of reason took over.
I went to Target and bought a $180 Schwinn trailer that has held up very well. It is in like new shape and we will probably sell it this summer since our kids too, have outgrown it. Keep in mind that it will be EXTREMELY hard to wear out a trailer. I probably have 200 miles total on mine and I would say that is quite a few comared to some.
Obviously 100 miles isn't very far by bike but with a child (let alone two) onboard that equates to quite a bit of time at family speed. We probably average 8 mph when we go on family rides, since my son is now riding his own bike. So we are talking about 25 hours of a kid sitting in a trailer. That is a LONG time for a kid to be content in a trailer.
We found that after about 20 minutes we were usually tired of listening to the kids complain and would end up heading for home. Basically what i am trying to say is that it is good advice to spring for a better quality bike. I personally don't think a trailer of the Burley cost is necessary for me.
Actually, it was a good decision. Like i said the trailer now hangs in the garage and is in like new condition still even though we used it quite a bit.