Yes it is. They both even share many, if not all, of the same filters. However, in a few cases, the filters have different names.
Nestopia is said to be more accurate and less problems with sound production
Neither core will run every game, so you'll probably want both if you're looking for maximum coverage. lr-nestopia does seem to handle some of the more finicky unlicensed titles, like 'Action 52' that lr-fceumm won't even launch.
My main question is, what should I set them to if I want a similiar experience like my old PAL tv?
I'm a Statesman myself, so that'll best be answered by someone else.
i don't really have time at the moment to get the color codes, and the way i did it last time was very tedious. if you're still around and willing to do another pull request for fceumm, that would be much appreciated. ifnot, i will most likely have time to put it together this coming weekend.