Welcome to the forum.
You have a tough decision there. When the wife and I were shopping for a new trailer, we looked at the same floorplans as the 831RLSS and the 831FKSS, but in a Rockwood models(8314SS
I liked the rear living of the 8314SS
(831RLSS) and the wife(DW) loved the large amount of counter space and cabinet storage of the 8315SS
As you can tell by my signature on the bottom, she won out with the 8315SS
We sometimes take our 1 grandson(10 yo.) and 2 step-grandsons(8 & 12 yo.) with us. We utilize the sofa bed and dinette for there sleeping arraignment. Of course, they don't camp with us all that often, so it is no big problem with the roomy front kitchen. I think if they camped with us more often, a bunkhouse model would give them their own space.
Good luck with your decision,
P.S. ...I have come to like the front kitchen model.