The sunburst finish is a stain that is sprayed onto the guitar after it is all built.
Here's a link to the Gibson virtual tour of their acoustic plant in Montana
http://www.gibson.com/Products/Gibson%20Acoustic%20Guitars/Gibson%20Acoustic%20Guitars/Montana%20SubPages/Montana%20Factory%20Tour/
If it's a Gibson you're matching contact me back channel, I may be able to hook you up with someone to get you cut-offs from the Montana plant. No promises though.
If you're ever in Nashville you can see mandolins (with a similar finish) being made at Gibson Showcase at the Opry Mills Mall.
The best guitar tops are solid sitka spruce. In my opinion Larrivee makes the best tops hands down.
Here's a link to their woods page
http://www.larrivee.com/flash/products/woods/woods.html
I wouldn't use spruce for the pen, although you might have a bit of spruce accent. It's a tone wood - which means it's vibrational characteristics are what's valuable. To vibrate well, it needs to be fairly soft yet also tight grained, which Sitka Spruce is.
I'd consider what the neck is made of. This has to be really strong to withstand the pressure of the strongs pulling constantly. Alternatively, what is the fingerboard made from? A lot of times this is ebony since it's really hard and won't show as much wear from the strings being fretted over and over again. The dots on a finger board are at specific frets, to help a player know quickly what fret she's on. These are often mother pf pearl, another pretty accent for your pen.
Good Luck!
Julia