As far as in wall tanks go. There are two common ways of putting it in the wall.
1. you can put it so the tank sits behind an opening in the wall. This type sits recessed into the wall and is the easier way to go. You just build a wall with an opening and put the tank directly behind the opening. This way will give you a 4 inch ledge in front of the tank if that is what you want.
2. You actually build the stand in to the wall as you build it. Typically the drywall is attached directly to the stand and the tank sits flush with the wall. This one is more difficult but I do like the differences.
I went with option two. Here are a few pics.
In my opinion, if you are confident that you can build a stand by yourself and you have some experience with building a basic wall then you could go with option two. If you are just confident in your wall building skills you could do option 1 and use a stand built by someone else. These are not the only ways to build in wall tanks just two different examples.