The torso is (obviously) from any one of several Han Solo figs. The arms are Sand Blue, and rather rare at this point in time. The belt comes from some UFO alien dude, and the pants are gray. (note: I believe the new gray would be best for the pants, but I do not have enough yet) The gun is from Little Armory.
The first part of the helmet is simply a white sports/skater helmet. I placed two pieces of tape on it to protect the rest, and then painted black where the helmet was exposed. When dry, take the tape off and you have a nice, crisp detail. (if you try this, test the procedure on something you don't care about first, as sports helmets are quite valuable). Testor's Black Enamel paint was used.
For the visor, I purchased the cheapest visors I could find. I then stuck the visor onto a dowel rod (thick enough it could just 'snap' on, but not too much to stretch it) and dipped it in a small jar of Testor's White Enamel.