Maybe you already noticed, but the overture keyword suggestion tool is really working sometimes and most of the time not at all.
But there is hope for you since one of the major players i this field is promoting there own tool:
free keyword suggestion tool from WordTracker
I have tried it, and it works great, and even faster then the Overture tool…
You get 100 related keywords And you can also get a estimate on the daily search volume at the end of the list.
Use the tool and add your results to you Google output that you created.
Form those two tools, you will have some good keywords to target based on what people are really searching for.
But of you don't want to do the hard work, here is a short list of commercial software tools that can make your life a lot easier.
I suggest you use these if you do a lot of research for customers to reduce your time.
If you just are working on SEO for your own website, the above mentioned free tools will do fine.