Shane, one of the other co-founders from Pistol Lake, here. We started Pistol Lake to make basic, well-crafted shirts that just fit. Happy to answer any questions!
1) How much are you trying to raise? What if it fails to meet the goal?
2) How exactly can I get a perfectly fitting shirt? What do I need/get to measure (i.e. is it two things and you get close or is it more)?
Love this idea for a company, by the way. I often have to find clothing in odd corners to fit my physique (tall, thin, long arms and torso). I've ordered tech shirts just because of how they fit (e.g. http://www.googlestore.com/Google+Redesign/Wearables/Men+s+T...) and buy lots of cycling oriented clothing as it seems to fit me better than "mainstream" clothing without being tailored.
2. Most people are adequately covered by the standard 6 sizes. Ours fit particularly well - how a shirt should. It is a lot about how it fits in certain areas of the body and then drapes. We spent a ton of time perfecting our block, specific for our cotton, and then expanded it with other shirt designs. We take it a few steps further and have made a number of other sizes to fit between a Small and a Medium, and one between a Medium and a Large, and then tall sizes, tapered cuts for extremely athletic people, and a relaxed cut for heavier.
We're working on the interface now, and will have it done when the campaign ends to collect measurements. We can match you pretty well with height and weight, but chest helps a lot as well. Whatever you're comfortable giving!
First time I'm doing something like this, so I'd like to make sure I'm doing it right :).