Ok, I normally rely on google tools for a lot of my info, but I need something that does a better job on keyword searching.

Let's say I am targeting 'highways of america'. I want a tool that will find plural versions, abbreviations, plural abbreviations, etc. Like 'hwy of america', 'highway of usa', 'hwys of the americas', 'highways in america', etc

Also, what would you use to target all the keyword variations? I've learned the hard way that if you don't post link variations for each combination, google won't rank you for them! I was missing an 'S' on a keyword variation that gets 135k exact searches per month, and wasn't ranked at all! In less than 12 hours after posting links for it, boom, #8 position! I thought google took into account things like that.

What is the best tool for both of these?

Thanks.