ok. I am trying to set up a new niche site. I have found a keyword that I like that has no competition for back links(easy enough to beat so it seems if done correctly). The question I have is:

When looking in adwords under the broad terms this keyword gets 5400 global searches a month with a little competition. When clicking to go the "exact" route, it ends up only being 170 a month. So, my question then is, do I look at the broad and then still go check out the competition or do I stick with the exact and expect that not as many people will be searching for that term? If I use the exact term though, and get to the #1 spot on Google, do I not only get access to the 170 exact phrase searches and a piece of the 5400 searches from the broad?

Sorry if this sounds a little confusing, maybe I am making this out to be harder than it is? OR perhaps I am looking at this all wrong?

Anyways, thanks to any who can help.