Following the perspective guides that were made the main outline drawing is drawn with Illustrator. Although the drawing could have been taken to completion with Illustrator, it will be faster and better (better being more important than faster) to finish it in Photoshop. The Illustrator file is exported to Photoshop 5 as a Grayscale at 600ppi, without anti-alias or layers.

With Photoshop, I always work on line art at 600ppi and at dimensions that are two to three times larger than the final print size.