First thing to know is that PAL-N is 50Hz, same as Europe... so you won't get picture roll.
We use PAL-I here in the UK, and Europe uses PAL B/G usually - but the difference is just in the sound carrier location. If you're using SCART, the sound is carried seperately anyway.
SCART provides three methods of getting the data from the machine to the TV: Composite, S-Video and RGB.
If your TV supports composite and your machine supports composite (which Amigas do), you will get a composite picture.
If your TV supports S-VIDEO only, you will get a composite picture probably, but possibly nothing at all.
If your TV supports RGB, and your machine supports RGB (which Amigas do) you will get a very clear picture.
Basically, I'd say you have a very good chance of getting a very good picture with sound, but you should invest in an Amiga->SCART RGB cable rather than using the composite video plug on the Amiga (or A520 modulator) itself.
Hope that helps!