So I have an NTSC PS2 and might want to pick up this game since it was from my childhood. But I have noticed that the WR is on PAL. Is PAL generally faster?

If I remember right, slidejumps are bugged on NTSC and NTSC also crashes in various situations where PAL wouldn't

Beta made a nice compilation of version differences, check it out http://beyondtwinsanity.com/versions/

Other than minor specifics though, all versions are more or less the same to run. Bodyslams are easier on NTSC, but you have the ol' slide glitch which gets real frustrating when trying to optimize movement as you're more or less just praying not to get thrown into wonky directions.

Slide glitch is really bad on XBOX 360 and it lags like hell, so as long as you're on NTSC PS2 1.1, you'll be fine