These are what I've been using. I'm very happy with them.
- Pentel Arts Pocket Brush Pen with refills. Right here.
- Faber-Castell Brushes and Medium tips. Right here and here. (I'm able to buy the Mediums individually at my local art store).
- White out pen. Here.
I didn't think I'd like the Pentel brush pen because it felt out of control, but now I love the organic nature of it. It's cleaner than using an actual brush for the artwork - no dipping ink or anything (I'm lazy). I've replaced the ink cartridge 3 times so far.
The big Faber Castell brush pen is to fill in large areas of black - nothing else. The smaller one fills in more precise areas that I'm scared to use the Pentel for. The medium is for really fine lines that I want to remain crisp.
The white out pen is because I don't want to edit too much in Photoshop. I like the idea of keeping this a little old school.