I can echo the recommendations for a non-slide 28A. It's a good travelling unit, but without slides, I would'nt want to camp for too long in it with 4 kids.
But if you're searching for such a rig, you might see if a 28D is also available. I'm not sure what year they stopped making them, though, so it probably would be an older model. And they weren't as popular as the 28A's. The difference is that in the back, instead of a queen bed, there is a second dinette on one side and bunks on the other. We almost bought one, but for us, there just wasn't sufficient storage space for the "baby support" items we needed back in 2004. :)
Good Luck in your search,
~Rick