I'm trying to plan for some multi-day trips this year, and one concern is replacing spokes on the road.

It seems I have at least two options:

1) Get a Stein Mini Cassette Lock tool (HyperCracker) and a few spokes of the appropriate lengths for my wheels.

2) Get some Kevlar spokes, which I see for sale at around $10/per on Sheldon Brown's website.

Are the Kevlar spokes all one length? Do they hold up for long trips, or are they a quick fix to get you home for a real repair?

Any comments on these or other options are welcome.