When looking for a bunkhouse pay extra attention to the length and weight ratings of the bunks.
Kids tend to grow ;), and as a parent of a 14 year old son who was 6'4" it was a bit of a challenge to find something he could fit on.
Also, if you can find one with more bunks than you need it will allow you to bring some of your kids' friends along, which as they get older can keep them interested in the whole thing. We were lucky that our three boys were best buds, but after the oldest couldn't make many trips due to work etc the void was quickly filled with friends, some who had never camped before...tons-o-fun.
You have hit the nail on the head with the "priceless memories" thought.....it is so true. Our longest trip was 6 weeks and 8500 miles, and even though it was 6 years ago our three boys (all grown now) still talk about all the 'adventures.'
BTW, that trip cost us less than 1 week in Hawaii would have run us.
Have fun!!!! Trust me, you will :)
Mike