Screen rooms

Do other campers (with specific experience) prefer screen rooms that are free standing or units that butt up to your trailer?
Do you have a preferred brand and model?
This explains what I'm looking for:
(posted in General discussions)
I'm looking for a screen room/tent that will butt up to one side of my T.T. (the Woodbutcher's Club Car).
I want something that constitutes a complete room with four walls because I want the screen room to function as an effective "cat pen", a changing room would be nice too.
But I also want some type of opening to the trailer in the wall that butts up to the camper.
My cat enjoys camping.
Can anyone help me with this?
Do you have a preferred brand and model?
This explains what I'm looking for:
(posted in General discussions)
I'm looking for a screen room/tent that will butt up to one side of my T.T. (the Woodbutcher's Club Car).
I want something that constitutes a complete room with four walls because I want the screen room to function as an effective "cat pen", a changing room would be nice too.
But I also want some type of opening to the trailer in the wall that butts up to the camper.
My cat enjoys camping.
Can anyone help me with this?