Thanks all for the tips!
The PAL-M encoder that I will have is:
https://pdf1.alldatasheet.com/datash.../CXA1645M.html
It was from a Playstation 2 "NTSC to PAL-M converter", but in reality is a RGB to PAL-M converter.
In fact, in theory I can convert the C signal from S-Video from NTSC for PAL-M (I have a VGA to S-Video NTSC adapter), but I fear that double color conversion will distort the color too much. Better to use this convertors and scalers I think.
Interesting the VHD-180; for me, solves my problem, since I have another notebook and a PC with VGA. For my relative, I will need the HDMI converter anyway. But I need to discover how much she wants to spend on that...
Another question: Quality wise, I suppose this VHD-180 being better than el-cheapo VGA to NTSC S-Video converter? The one that I have (these cheap) distorts the red too much (over saturates it); the native NTSC (or PAL-M) DVD and DTV have more realistic colors than it. I use this NTSC converter with my newer multinorm TV's that have NTSC.
Same from notebook; even with careful adjustment, the image is not so good like same film/picture (for example) running on a DVD that have native old analog format. This will be my hope also with something like the VHD-180.
Ah, the SECAM color system... Since here is too far from countries using this, and I not travelled to countries using SECAM in the analog era, I never watched in person a TV using this system.