kott, there are a couple threads about adding the sliding decks, which a number of people have done. The dealers won't be able to do it, since it is not an optional add-on. Your only way to get one if you already have a rig without is to trade your standard deck pieces with someone who doesn't want their sliding deck.
If you're not able to source one,
this is the cleanest (non-sliding) setup I've run across. It's a simple build and is perfect for what you're after. Note that picture is posted in one of the threads about adding the sliding deck, so click out of it to see the rest.
I am actually in the same boat as you. I really want the sliding deck for the same reason, as I'm ready to buy a '17, but they aren't available on what I'm after without KDSS and in my color preference. So, I will be having to go that alternate route until I might be able to find someone to swap with. Who knows, I may prefer the custom option better.
I'm not at all sure what Sparky is going on about, as those remarks are off the wall to say. Going back to the second generations, simply remove the seat bench, then a 6' 6" guy should fit without a problem. I've got 677 nights in my '02 doing just this setup without having the need to move much gear around. That's certainly more cost efficient than an awning and a cot, not to mention less time to set up, and less gear. Note that this is for a single person setup. Obviously, if you had two, then absolutely, gear would need to be rearranged all the time.