TubeSift is my go to tool when I am looking to run YouTube Ads.
The idea behind it is to make sure that finding keywords and videos to target is easy as pie...
Prior to this tool it was a HUGE headache to see which videos could have ads run on them, but not anymore.
All you have to do when you have TubeSift is plug in a keyword and then let the tool find all the videos that can be targeted.
Best thing about this, I am friends with the owner and he gave me a special discount code to give out to my audience! So you get it cheaper than everyone else :)