When you say "big box" does that mean a store like Home Depot?
There is a Flooring Store near me (a small, privately owned store that's been in business for a long time). There is also a private contractor guy who also builds custom homes in our area that has been highly recommended to me by a friend. I get the impression that he and his brother do just about anything you need (he also contracts out when it's something that he doesn't do). He's coming out this weekend to talk with me and give me an estimate.
What installation guarantee do you really have when you go with a small store or a private contractor, if they go out of business, etc. Maybe I'm being paranoid, I dont' know.