4) Electric Eraser.
For work on the board, I find nothing better at getting at those tiny, tight lines than an electric eraser. Staedtler makes a dandy electric eraser that's affordable at under $15. I ordered 70 extra eraser fills for mine, and it's one of my favorite and most useful pieces of drawing equipment.
5) Speedball Super Black India Ink.
When I ink, I use Speedball Super Black ink. It's a solid ink that plenty thick and covers well. It can easily be thinned down using a few drops of water also, or with thinner inks like the modern Black Magic Ink. For brush inking, I highly recommend it.
6) Raphael Kolinsky Red Sable 8404 Brushes.
I've found no better brush for inking. I use the #2 and the #3 Raphael brushes. The hair used in Kolinsky Sable brushes comes from the hair of a mink in the weasel family found in Siberia and Northeastern China. Kolinsky hair brushes are considered to be of the best material for oil and watercolor brushes because the hair is strong, springy and retains its shape, holding a very fine point. If you treat these brushes right, they will last for a long time. I use several Kolinsky brushes, but I've been using one particular Rapheal Kolinsky Red Sable for over a decade now. and it's still going strong, and retains a nice point! The 8404 and the 8408 series of Raphael brushes make for excellent inking brushes.
A good brush can give you the best range of line for inking, and I highly recommend Raphaels. Only the Winsor and Newton Series 7 brushes come close to these.
A number of art stores carry these brushes, but they tend to be difficult to find. Your best bet to obtain them is from dickblick.com. Here's some links:
Raphael Kolinsky Red Sable 8404s:
Raphael Kolinsky Red Sable 8408s: