Yarn Dilemma

If I make it to 50,000 words on my NaNoWriMo novel, I get to order a skein of Socks That Rock yarn from The Fold.  I think I can make it.  Question is, which one?  I've narrowed it down to these one of these:

• Harvest Moon
• Mesa
• Moss Agate
• Rocky Horror
• Sandstone
• Seal Rock
• Tiger's Eye

Which one should I get?  Drop me a comment and let me know.  If you've used this stuff, I'd love to hear from you.  The colours are amazing.  The yardage looks a bit low, but I have reasonably small feet so I should be OK.  I'm planning to be done with the novel by next weekend.