Manga U has a nice collection of Tachikawa nibs and holders they offer as The Ultimate Manga Pen Set for $25.
I prefer fountain pens for that kind of work (we've been over this, haven't we?
), though $25 for the dip set is a decent deal. I have (and still use) an assortment of dip-pens, but these days I use them to draw circuit boards (thin down some inexpensive model paint and draw with it for easy and artistic
I'm more the Faber-Castell or Sakura type.
I used to be a marker-point pen guy (Pigma Microns FTW!!), seemed a decent enough replacement for gravity-feed pens like the Rapidograph, but... no. I drop pens way too much, and the first time you drop a marker pen, it eventually hits the point and it's done. Even if you don't, the points eventually wear or dry out.
At least, they do for me.