In all honesty, I have never seen any Kosher prepared meals for hikers out there (very limited niche I would hedge).
On the other hand, it needn't be an issue: just figure out what they like to eat and then use books and websites to get meal ideas (heck, this is how on my website I make low sodium recipes for myself: I take what looks good and then change ingredients till it works for my diet.)
One thought as well is also check out natural foods stores for the higher end of organic companies that get Kosher certified.
And truth be told? Being that I have a special needs diet....I would NEVER expect anyone else to plan my meals. I would do it all myself....and I would suggest to the friends that they start planning <img src="/forums/images/graemlins/wink.gif" alt="" /> This way they know it is 100% Kosher.
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Lightweight, but not freeze-dried:
Take a look at the Fantastic Foods line in your nearest grocery store. All of their stuff is vegetarian and, IIRC, marked as Kosher. See if any of the couscous, bulgur, or other "instant" starches are also marked as vegetarian or Kosher, so you can add them as extenders. In the case of the FF soups, they do fairly well when thickened with some couscous, rice, or mashed potatoes, etc., as a meal. In a pinch, add crumbled matzo crackers.
If you are going with vegetarian foods, you won't have an issue with mixing meats and milk products, so you can supplement with cheese, when desired. If the people you are concerned with need Kosher certified dairy products, they will e more expensive, but should be something that you can locae.