Creating high-detail bitmap wiring diagrams

What's the best object (Form or PictureBox) and ScaleMode (Twips or Pixels) to write thousands of lines and text for a high-detail wiring diagram, then save to a bitmap file, then open file and read, scroll, zoom in zoom out, etc.

The bitmap files could be 5 inches wide and 50 to 100 inches in height.

Thanks-lp