We have a Cabelas dome tent, forget the model name. Outfitter? It is pretty much near their top of the line, and I would bet the most expensive dome they have. Ours is an 8 person with fiberglass poles. They now sell it with either fiberglass if you want to save cost, or aluminum if you want to save weight. It is a 6 pole dome with three that meet in the center, and three that support around the side walls. It has almost 7 feet of height in the center. It is probably close to 20 years old. It has weather a LOT! We had it set up in a bad spot during a downpour. We came back and it was floating in a foot of water. We opened the windows, pulled the gear out, picked it up and moved it to higher ground and NOTHING was wet.
When we got ours, an optional Alaskan Vestibule was available. It has been great. It attaches to the fly in front of the door and is about 5' high and 8 foot long. It is horseshoe shaped, has screen sides on both sides and a rain fly that zip down over them to seal it off. We put a porta potti at the far end of it and love having it instead of night time runs to the bathroom.