depends if you are willing to spend money on it or no.. Google adWords are free and there are so many other paid services that have something more to offer. but whatever it is adWord is capable of doing the things that you want to get done..
There are many sites which provide keyword research. But i think google adwords Keyword tool is best. One more thing. you can make account in Google Analytic and check for result for your chosen keyword.
Have good experience with : https://adwords.google.com/select/KeywordToolExternal did not used any other keyword software but tough competition between these 2. So i will try freekeywords.wordtracker.com
google keyword tool works well, just use your mind.. you do NOT need to purchase a licensed software.
Now I am wondering how many daily visitors you get to each of your sites when using only free keyword tools?