Fireplace Install

[Finfeatherfur]

Looking for a little input from all those DIY guys out there. I have all the tools needed and feel very comfortable on a project I am getting ready to tackle at our new camp in Ms. We will be adding a fireplace to our little slice of heaven and need some ideas. I will be going with the "insert" type wood burning fireplace and will be boxing it in with either cypress or pine tounge & groove to keep with the rustic setting of the camp and avoid the cost of a mason.

I have a roofer installing a new shingle roof this week, so one question I have is should I go ahead and do the chimmney now since he is there. If so, how will he know where to put it? Also, will I have some room to play on the stove pipe if he is off in placement?

Any advice is appreciated!