So which configuration is better?
If it were me, I'd stick the 1 meg Agnus in there. You'll show only 512k Chip RAM, but if you get an A501 then you can do the Rev 5 hack to give you 1 meg of Chip ram. Then you stick the 2 meg of fast RAM back in. Then you have 3 megs or RAM. That's how I remember most A500s being set up.
I think the best though would be to stick with the 2 meg Chip, then get some other kind of fast ram expansion.
But there were quite a few games and demos that required 1 meg Chip ram later in the life of OCS/ECS.
Either way with the 1meg or 2meg Agnus you'll be able to do PAL. And I know exactly what you mean about the audio finally syncing in demos. I think it went faster in NTSC so the music would end before the demo a lot of times. Demos like State of The Art, the audio is synced to scene changes and things, so it's kinda weird.