for a new site, you may want to direct your attention to keywords that are not used by big sites. just a thought
I think you can try Micro Niche Finder, Keyword Elite or Market Samurai! They are all paid softwares! If you want a free solution try Adwords External Keyword research tool or Wordtracker!
I typically use SEO Quake toolbar in FF to look at keywords and meta tags. You may find them useful and you can export the values in txt or csv format. Apart from that Google Keywords Tool is good option as well providing a great deal of information to you.