Maybe some of you may be interested in this solution I prototyped at our dojo, it's a hanging makewara.
As you can see, it's just two planks of plywood with EVA foam spacers. Very easy to build, extremely affordable, good for small spaces too.
Got the idea from Higaonna's book on Goju-ryu traditions and practices, the original is a much more sturdy object made with hardwood and rubber spacers.
Although there are no descriptions in the book (or anywhere else in english I could find) for sizing, actual installation and proper use, we got pretty close to the feel and function of a more common ground anchored makiwara.
The ones in the pictures are made with 34x16 planks of 10mm plywood and small cuts of cheap tatami mats stacked to 2cm high.
Mine is the one in the first picture, I leave it at the garage and give a couple of punches on it every time I pass by. It's easy to customize it for your own needs, to make it more pliable it's best to increase the length of the boards; To make it more friendly or aggressive just change what ever you use for cushioning the top board (I don't want my hands to become demolition balls, so I'm happy with an old obi); And put hooks in the wall at different heights for different people or exercises.
They are, so far, unbreakable on regular use and light abuse. You can see mine looks a little beat up, its just that we are having a very cold and wet winter this year (for our standards :P) and plywood gets mold VERY easy, a quick buffing with sandpaper on spring, a new coat of oil and it will last for a long time.
Besides the more obvious uses when hanging on the wall like mine is, you can take it with you and have a very complete conditioning session. Place it sideways on the ground in a 45° angle with the wall and you can practice conditioning your feet all around. Sit on a chair and use the sides to condition the bones in the forearms and elbows. Place it flat at floor and you can practice being mounted and hitting an adversary at the ground.
Please, feel free to build your own and let me know what you are doing with it so we can make this thing better and better.
If you have any doubts on how to build it, just let me know o/