There are solutions to sleeping in the truck - Bed Tents, RTTs and Flippacs for example.
I'm pretty sure can get the manual in a DCLB sport and SR5 trims - you might have to order it in, or shop around.
You don't say where you're at - but you should know that the Toyota build-your-own thingie on the website is zipcode restricted. The truck I bought also couldn't be made according to that thing, and yet there it is in my driveway. The only way to know is to talk to a salesperson who knows how to find them. Not all of them do, so you should shop around.
At the risk of being all Zen, the e-locker is an advantage when you need a locker. At all other times, it doesn't do much. So, are you planning on spending a lot of time in situations where a locker will make the difference ? Then you may have to compromise some other feature to meet that need. If you aren't, then it might be expendable in favor of getting some other feature you would use more, like a long box.
A locker can be added later on, at some expense and effort, but then, if you plan on doing any real wheeling, you'll need to open up the diff to regear anyway.