Brettski,
I am sure you have thought of it, but food for thought: When you turn the upstairs into a workshop, remember you might be building some rather large projects at some point and need to find a way to safely and as easily as can be, transport the materials and finished project up and down those stairs so make sure they are wide and your front door as well. You might want to move the stairs/front door over so they are inline with each other because bending lumber around that corner is going to be a big can't do unless I am missing something.
