Here are couple of font packs I built. The first one listed is for various source code editing tools and the font family is call Paragon Code. Depending on your editor, monitor, and age of your eyeballs, you will want to experiment with selecting from the various sizes and weights of the font.
I actually prefer using the medium weight point size 10. This allows 70 lines of very readable code to fit in RDi in full screen mode (As seen below).
The second font pack is Paragon Mono. All of the sets of fonts essentially look the same, with the Paragon Mono being developed first for a project I did to replace spooling on the IBM i. This font had to meet the requirement of printing 132 column reports on standard paper in portrait mode, while making good use of the entire page in an effort to make the report very easy to read.
The third font pack is a further extension of that printing work and takes into account the various CPI settings that can occur from old fashion spooling. The Bold versions of the fonts are designed to make the character heavier while occupying the same mono-spaced character square. This font pack gets its name from the product it was developed for: CRIME. A software package on the IBMi.
They are all mono-spaced fonts of the same family of glyphs with slight weight, height to width differences. All of the fonts eliminate any confusion with 1, L, I, i, l, and 0 vs.O as seen in this sample of Paragon Code Medium.
You will find the underscore to be full width of the character block, and the upright bar to be full height of the character block. This provides some rudimentary abilities to draw boxes and such. There are also several special line drawing characters that you will just have to go check out. You can make some rather cool line separators and comment markers.