Looking for a monitor about 27 inches with USB-C, DisplayPort output and audio output?

I recently bought a laptop with USB-C Thunderbolt 3. I want to take my laptop as the host and my tower machine just to play. But this should all run on a setup. What does the same keyboard, mouse, speakers and both monitors mean. The 27 "monitor should have a USB port to connect to my laptop, DisplayPort input and output, or HDMI with output, audio output, 2 USB ports for the keyboard and mouse, and if possible a USB-B (the same The DisplayPort / HDMI output should be for the second monitor. The USB-B port should be for the Tower PC, so that he can also access the keyboard and mouse on the monitor. And not expensive, preferably under 300 euro.

Such a device is not known to me.
And if there were such, then probably more for 2000 euro

Why do not you just control your laptop with Remote Desktop from your PC? Requires only a network connection of laptop and PC.

Your idea does not work that way:
There's no monitor with two USB inputs, which then also serve the same outputs. That would also be very problematic, because over USB also power supplies run and a double feed can't work. The same applies to the sound.

A common keyboard, mouse and sound would go through real Bluetooth devices that do without proprietary dongles. With the PC you must then retrofit a dongle. Keyboard, mouse and sound completely simultaneously via Bluetooth could also be problematic, so I would solve sound differently. There are solutions with multiple inputs, e.g. Optical and 3.5mm jack. The PC then optically coupled via fiber optic, is also electrically useful to avoid pounding circles.

Alternatively, there are switches that solve all problems and at least up to 60 Hz and 2K work properly. The useful costs over 200, -:
https://www.reichelt.de/displayport-1-2-kvm-switch-4k-60-hz-mit-usb-3-0-und-audio-delock-11467-p252696.html?&trstct=pol_4&SID=92XO5RpqwQATUAAAL1tyc582a50b46985ad20197cd2d647834835

For all solutions, you only need a "normal" monitor with two digital inputs, 300, - € but is too short as a total budget.

I have seen some between 200 - 300 euro but there are usually only 80-90% of the connections I want to have. And I mean the two USB ports for mouse and keyboard and another USB-B port where the B side of the USB cable comes on the monitor and the A side on the PC. Remote Control I do not want because at least one PC must be on, and the idea is that I do not always want to turn my gaming PC only on the Internet to surf. Audio is transmitted via USB-C from the laptop or from the gaming PC via the video cable is HDMI or DisplayPort. And I wanted to solve the problem with the switches with such a monitor, as a switch of my request should feel at least 80 to over 100 euro costs.

The double USB hub is the sticking point:

Of course, it would be technically possible to pair two USB inputs with the same outputs, to switch them if necessary, and even to implement a controller that uses the graphics signal to detect when which source is active and then toggle the USB circuit accordingly.

But then the monitor manufacturer would have to install for a rarely used feature exactly what else a switch manufacturer uses.

Although I'm reasonably up-to-date, I have not seen any solution so far. For the professional sector, this will rarely be interesting, because you either work with notebook and docking station, or in permanently stationary workstations uses virtual machines.

For the few cases where you want to use a workstation with two PCs, there are the switches for switching. For the professional field are 300, - € as well not much money. These then have the huge advantage that you can use "normal" monitors, can also use two or three monitors and that arise in case of defect of the monitor no high cost.