can i get an official scart cable and some sort of scart to hd15 or rgbhv cable and play my ntsc games (ntsc console) in progressive rgb?
You'll need an official component cable. These can be modded for RGB output instead of component, and if you enable progressive scan (for those games that support it) you'll end up with high-res RGB, which is VGA.
You can't get 31kHz from the analogue port.
i was trying not to mod the cable, i'm not too comfortable with soldering irons. i know the qoob chip can force progressive, can it force rgb?
The converting hardware is in the cable. If you don't mod it, you don't get VGA. If you have a PAL GC you can get low-res 15kHz RGB from the multi-AV port, but that's it.