Hello az_angel -- welcome to Air Forums! Are you researching to purchase used or new? For the latter read through http://www.airforums.com/forums/f274...ued-47645.html
. The Classic thermostat has a bit more flexibility with zone controls (different temp setting in 2 or 3 areas of trailer depending on length). Insulation is no different, so I'd not say it's more efficient. In the Southwest you'll want the biggest capacity air conditioner option you can set your hands on. Then you'd be talking a plug-in campsite.
If boondocking you can buy an inexpensive cigarette lighter inverter (see Amazon?) to let your laptop recharge off the coach batteries. My laptop brick says it wants 1.5 amps input, so 180 watts would be the smallest I'd want. Note that your tow vehicle will recharge drained batteries only slowly (300 miles of driving? 400 miles?). Drawing the coach batteries below 50%
can damage them and cut their capacity and useful life. I've seen one long night of DVD player use drain the battery in a truck.
What will your tow vehicle be? Do you have a general length range in mind?
The sideways bed under the panoramic windows is somewhat narrow at 48" and others say it's hard to access to make the bed. It's in the 16' Internationals and 20' Flying Cloud. Other sideways beds (queens) begin to show up in 25' Flying Clouds.
How many people will be sleeping aboard? You ask about the L lounge. I'm pretty sure the factory wouldn't add one to the rear of the 20' Flying Cloud -- there'd go all your plumbing.
A mix of old and new Airstreams show up at rallies. No area is more active at having rallies than the Arizona area. Check our rally calendar. Walking through others' coaches is the best way to get a pre-purchase sense of what is practical and which Airstream might have the capacity and features you need. Check the Rally Calendar at the top of the page -- bring that ol' Eureka Timberline and tent among silver!
Beyond that -- only a trip to a dealer is going to give your an actual idea of what the fabric options are right now. They lock into one large quantity of any fabric and when they're gone, they're gone. Go to Colonial Airstream's site
and scroll down -- there'll be plenty of pictures if the unit is in stock or sold.