I LOVE this piece! Professional grade heroes! (naturally) It says this is digital art, I'm curious what program you use? I have a Bamboo Wacom Tablet that has the Auto Sketchbook Desk and I just haven't mastered using it yet.
I'm glad you like it so much. The line art is just graphite. after I scanned it I e-mailed it to who did the colors in photo shop. I'm not exactly sure what else he uses. When I do color my own work , I normally use photoshop and my wacom tablet. I use the 11x17 one, but I suggest whatever is comfortable for you.