I don't know about oak gall or the other things you mention.
Regarding ink, I've tried Parker Quink, MontBlanc, Pelikan, Herbin and Private Reserve. Personally I prefer Herbin as the colours seem more natural. Private Reserve colours jump off the page and are quite intense, which can be good in some cases. I've heard good things about Galerie Jansen (German made) and have a catalogue, but haven't placed an order yet.
There really is a lot to choose from today, my experience with MontBlank ink is that it's best to avoid (yes, even though they recommend it for their own pens).