For a 4 seat RZR, you'll need at least a 12'6" garage. Stock, they are 12'2", and then most toyhaulers of this type have the rear patio option, so the "walls" for the patio take up about 3-4" of room.
Our Keystone Impact 351 has most of what you mention in your list, except for the 2nd bath. Garage is 12'6". But, we're just over 38' long. We also do not have a dining table in the main living area, so that might be a negative factor with kids. There's a portable table you can set up in the garage area with the drop down bed which converts to benches.
Our neighbor has a Fuzion 371 that has what you list, including the half bath, but only 11' garage. But it's 39'. Also again, no dining table. We've found very few toyhaulers with separate garages under 40' have a dining area. I can't even think of a single one we looked at that had one to be honest.
