Hello guys, thanks very much for your answers!
@bello I guess a device like that would add a delay considering that device offers several functions like scaling leading me to be pretty sure that it contains some kind of chip doing calculations, which obviously will take their time.
@MrCoffee The two CRTs I could currently experiment with are both PAL TVs which came with SCART input from the factory, so I'd need to try if they support the PAL60 mode, otherwise of course those CRT would not be suitable really for retro gaming.
What did you mean with the questions regarding the wanted resolution. I'd want the best faithful resolution a particular console would output, so I guess the resolution I want would vary depending on the system that gets emulated and even which game. The last link you posted is a about CRTSwitchRes which I guess will deal with that. I'll now read through that forum to check out what they are using in terms of hardware & cabeling and I already found they provide MubuntuOS which already contains all the needed software so that'll be handy for a first try.
The device you linked to seems to be awesome, but component input on a CRT-TV in Europe is pretty rare on most likely only found on 100 Hz televisions which suck for gaming though because they introduce lag.
Just today l I also remembered that about 14 years ago some people involved with vdr, an awesome linux software to receive TV, were driving CRT-TVs from their VGA-outputs and already discovered that that part of the project was called VDR2SCART and they also developed a cable for that. So I'll check that out and see if it's also fitting for gaming purposes at 60 Hz.