Sorry I didn't see this earlier, I've been to Amsterdam a few times as I love the city. Not only the prossies but the city itself is beautiful and wonderful to visit, though it is notoriously expensive.
Most of the good advice has been distributed already, but I will say you should usually steer clear of the "main drags" and by that I mean the windows along the sides of the canals. Those are mostly tourist traps. I'm afraid I don't remember the name, but the most popular street with the least amount of rip-offs that all the locals go to is the one really, really, narrow passageway where you can barely pass other people shoulder to shoulder. That alley which leads from the canal to the back street, that back street, and the covered area connected to it are generally the best areas with the hottest girls.
I've punted a lot in the UK too but I can safely say the hottest girl I've ever had in my entire life was in the RLD. There are some there that could be supermodels. Blew my mind.