Seriously Considering - Your floorplan opinions please

Hi All,
I am new to the forum and very happy to have found this site. I have been reading through many of the threads and it's nice that this site exists! Seems to be a lot of nice folks here, and some terrific information!
I am seeking your advice/opinions on a floor plan.
Here is some background info (and I will try not to be a windbag...)
Hubby & I have decided on a TM - what a great concept and quality. What we cannot decide on is a floorplan. We are a family of 2 adults, 2 teenagers and 2 labrador retrievers. We have narrowed it down to either a 3124KB or a 3124KS. Here is the thinking:
A 3124KB provides the extra double bed that one of the kids will use. The other kiddo will use the couch/bed. The dogs will be in the King bed with us. (yes, they are spoiled to death!). The pro of this floorplan is obviously the extra double bed. The con is the seating arrangement. Not a whole lot of room with the 2 couches. It's ok, but not great.
A 3124KS would provide a couch & a chair (actually, 2 - we talked to the dealer today and she said they can remove the 3 drawer cabinet and add an extra chair.) I much prefer this arrangement,( a couch & 2 chairs) as it feels like a more useable living space. But, then the bedding arrangement becomes a slight issue. One kiddo would have the couch/bed and we were thinking that the other could use a twin size air mattress. Is this feasable? If you have a 3124KS, would there be enough room to move the chairs out of the way to inflate a twin size air mattress, or should I let this line of thinking go?

Your advice and experiences are much appreciated.

Thanks!