Advanced Minds

Having read a few threads on this subject, I still have some questions: I am currently using a Moss Big Dipper (4 season 4 man dome) and a Moss Outfitterwing (large aerodynamic tarp).  I love both of these, and would recommend the Outfitterwing in particular as it is unusual and gives you amazing coverage from rain and sun (useful in the Pacific Northwest).  If you set your tent up under it you get the benefit of ot using your rainfly but you are  still out of the rain. Question:  I have two kids and am finding the 4 man tent cramped.  Should I buy a large cabin tent or a large dome tent (like the Kelty at Costco)?  Should I buy a cheap Coleman (like a 2 room cabin on sale at target for $157) or stick to the usual policy of 'buying quality'.   In this case weight is not the ultimate consideration as it is for car camping. Finally - are those screened gazebos for under $100 worth using? Thanks in advance! Jim Wiggins