Yes, amazon! I think Windsor and Newton drawing inks are the most popular. They're made with a shellac binder. Be careful though - I've used shellac based inks that ran a bit, which was annoying, but then again, I did that a while back when I wasn't very used to watercolours / drying times, so that might have just been my fault LOL.
I actually just use watercolour again at the end! I just mix up a really dark colour (usually purple, blue, magenta, or black) depending on the mood I'm going for!
As for pens, the general rule is to never use them in fountain pens (they will dry up and clog it, and you'll have to throw the pen away!). I usually use dip pens or just plain brushes! liner brushes work well because they've got long bristles and are a bit stiff, so they're pretty easy to control.
Hope this helped!