Check out Amazon for Suptek mounts... They hold up to 22 or so pounds, and can hold any size monitor with vesa mounts as long as the weight is right ( They say limited to 27", however there are plenty, including myself, who have larger monitors mounted and they work great - check out the reviews )... I have one on the wall, one on the desk and they are fantastic. They have all of the features you want for around $20 and $30 shipped depending which one you want. European prices may be different but here are the links...
This is the wall-mounted one.
https://www.amazon.com/gp/product/B00Y8ERSPY?ie=UTF8&tag=acecool-20&camp=1789&linkCode=xm2&creativeASIN=B00Y8ERSPYAnd this is the desk one I use:
https://www.amazon.com/gp/product/B01AXE2O6K?ie=UTF8&tag=acecool-20&camp=1789&linkCode=xm2&creativeASIN=B01AXE2O6KBoth are typically the same price, but the white one can go as low as $18 shipped. For some reason the desk clamping one is $43 now, but it is usually $30, and sometimes a little less.
Both are fully adjustable and they are essentially identical except the arm to mounting option and the mounting option. The cable management isn't that great - the plastic sheath which goes around the forearm has a track for 2 small wires, I had to use tape to put a power wire and a thin wire in - now I just use zip-ties... However, aside from that shortcoming, these seem to be the best mounts I've tried, used or found because of the fully adjustable gas-spring system. You can adjust it up to the 22 or so pound mark to make moving the monitor as easy as using a single finger. You can Pitch, Yaw and Roll the monitor on top of being able to set it almost flush against the wall to about 2 feet away from the wall. The gas piston adjusts the weight for moving the monitor along the up / down axis. The forward / backward and left / right axis are on pins which aren't difficult to move the monitor with. And the pitch, yaw and roll angling is along another path - you can adjust angling with 2 bolts, and the gas piston is adjusted with a hex key they provide and they provide a simple wrench for the 2 bolts.
Photos:
This one shows the new 4k monitor ( I haven't purchased the wall suptek in this photo ) but notice how low to the desk I can put the monitor... All the way down to it so an excellent range of motion. I got one for the wall for the top center monitor so when I have to lean back in my chair ( quite often ) with neck support, I can pull that monitor back too and it ends up looking like a cockpit. Right not the 2 right monitors are not hung.
https://www.dropbox.com/s/h9at76fug0hi1oy/20180310_045900.jpg?dl=0The one downside to the mounts is the cable-management as I touched on. On top of the poor cable routing slot, the plastic sheathe which goes over the bar to make it look 'better' blocks the range of motion. I have actually removed the sheathe off mine, and the other one which screws in, on the top monitor so it could be lowered a few inches more, which shows a an unpainted metal bracket and the black piston. I'd be happy to show that that looks like, but since it is on the top one it isn't seen ( especially when the other monitors on the right get hung again when I buy a few more of these mounts ) and the extra range of motion without is worth it. I may end up painting it with piano lacquer later or regular paint... We'll see..
One of the reasons I did NOT go with the dual, triple, or double-decker hex or quad mounts is because they all have problems with SAGGING. Every single brand that I saw has this issue... The suptek brand does offer a dual one which uses the gas piston system instead of fixed arms which means even if there is a tilting issue ( since they both hang from one bar ) they can be adjusted to line up as you want them so I am considering getting a dual version to try ( and it has a tall pole so I could actually get 2 and only clamp one to the table, then use both duals on a pole for my center and right monitors, then for my left I'd use the current wall or table mount )..
As far as how much distance from the vesa mounting point to the wall when the monitor which is wall mounted is when it is set back as far as possible ( and you can rotate the hinge a bit to actually help with it, or kick it out a bit, and doing that also offsets it a little left / right depending on the way the < elbow > hangs so if you don't mount it exactly how you want it, you can just move the > angled part to the other side and it should be centered. Anyway, the distance from wall to vesa / back of monitor is: approx 3.5 inches....
The 3.5 inches comes from the back of the Angling portion of the mount so there really shouldn't be any other mount which could do much better, if at all since this is pretty heavy duty. and 3.5 inches isn't that much - I'd consider that pretty flush against the wall, especially as the monitors are typically tilted anyway which leads to about that difference if mounted as a tv, or non-centered position... IE: If I had mine flush against the wall, the bottom of the monitor would touch first before the 3.5 inch long pivot / angling axis does - but then again I may angle mine more.
If you want up to date pictures let me know.