Hey Ryan,
if you don't get data from google keyword or maybe google insights for search , chances are, there won't be too many searches. But as you say, the long tail (longer, less competitive but highly relevant) queries can bring valuable traffic as well. Prices for ads for those keywords will also help you determine the degree of competition for a term.
I would probably compare your ranking for some of these longer tail keywords (e.g. Position 3 in google), to the data in google analytics, there you can check, how many people came searching for each keyword. Or you use google webmaster tools, they will actually tell you what the rank in google for each keyword was. In my experience, data isn't as precise as in analytics, but it will still help to evaluate if going for longer, niche keywords would be the right thing to do. The most important factor is of course to check, if those customers actually convert and deliver any kind of revenue for you.
Hope this helps a bit, btw, the site looks great!
Cheers
Frank