HighnDry wrote on Dec 30^th, 2014 at 10:36pm:

Old Salt, I like the SR18.5 too. My only issue there is whether there is room for 4 with 2 full adult portage packs, a food barrel, and 2 kid packs? Hmmm.

Yes, and you can get creative with gear stowage, such as small drybagging some of the lightweight bulky items (sleeping bag, clothes, etc). It gives the kids something to carry and it gives you the option of stuffing them under the seats an behind the stern seat. 
At 10 & 12 y/o, your kids should be able to sit side by side in the SR18.5. Otherwise I've arranged for one to sit immediately in front of the stern paddler and the other right behind the bow seat. It was necessary to relocate cross thwarts to do so. The side by side works good, but your kids have to get along well, so be the judge.

-YB