Narrow Search by Geography

I'm in the research phase exploring the search fund model. I'm wondering how you have thought through the issue of narrowing your search based on geography. Of course there are many variable to consider within this question (perhaps New York would offer more opportunities than Oklahoma City). In my particular case, I'm trying to understand how realistic it would be to design a search around a single mid-western US state (Iowa). Do you think that this is an important part of designing your quality of life, or does it result in a deal flow too low to support an effective search? If you do support a geographically based search, what criteria would you consider to be key?