I modeled the very basic shape of the figure, chair, and table in Zbrush. Everything else and all the detail (including the EXTREMELY TEDIOUS shirt-texture) was done in Photoshop 
wow thats amazing!! Do you have specific brushes you use, or do you use the basic ones? I never quite got the hang of making my own brushes. I use these a lot shottsy85.deviantart.com/art/M… But I mainly wound up just using the top two because I like the painterly look I can get from them.
I have a HUGE library of custom brushes but I only use a handful of them. Quite a few are actually very similar to the brushes you link to.
oh awesome! I REALLY want to learn to make some sort of better pore brush for male faces, and a scale brush for dragons. I a lot of times just do it all individually, but it would be nice to figure out how to make a nice quicker one that doesn't look cheap and retarded.