I used to use a program years ago called sitesniper pro. It would take keywords and find sites in google top 10 results that have adsense on them. (so you can put the url in adwords under site targeting campaign and advertise on it) the software and the website are no longer working. but it figure it is pretty simple so someone has to have made similar. please let me know if you know of an alternative.
Well I do not know of anything that does exactly what you want, but from your wording it seems that you hadn't used Adwords since long ago. So it might be a bit of a stupid suggestion but have you considered the Google Display Planner inside the Adwords interface? I'm not sure if it existed years ago, and if it did, it was definitely different than it is today. It allows you to find target websites through keywords/categories and you can also sort them by traffic/visitors, so I think that would do a lot of what you're looking for. To access the display planner (make sure you're logged into Adwords): https://adwords.google.com/da/DisplayPlanner/Home