Hm... So far as wigs go, you might have to end up styling a longer wig that's the right color. I read about people using the Scruffy wig from Cosworx, but after the merge with the main site, the preview photo changed so I don't know if it's still the same style.
The jeans, however...
I assume the tutorial you found was this one
from deviantART? That's the only one I really know of, haha. But yeah. All it really calls for is one to be able to sew in a straight line for each "ring."
On that note, if anyone suggests you just draw them on with a Sharpie... don't. Really.
I suggest you don't use the khakis. If anything, just use plain jeans. At least they'll stick to the color scheme at a distance.
... Yeah, I'm not really much help, am I? -shot-