What's the fastest console and version (NTSC and PAL) to play this on? (I play the PS1 disc on a PS3 on Namco Museum Vol. 1 PAL version)

I can confirm that an NTSC atari 2600 cart can get the same in game time result on a PAL machine as an NTSC machine. I don't know if a PAL cart would change that - some developers tried to improve code (often by reducing graphical changes) to make PAL games less slow looking when compared to NTSC games. This often was the case for games reliant on speed such as beat em ups. I don't think it was common practice on the 2600, but it might affect the PS1 version. Would require comparisons to test.