I've managed to create a new Raydium compatible 512x512 TGA font file using an ugly way, but it works.
This example font is intended to be used for the console:
font4.tga Look and see!
IMHO, it looks much better than the "official" font2.tga one on higher resolutions and is may be a little bit to small for 800x600 and lower resolutions.
Short How-To create a new font:
1. I'd to emulate a Windows session to use this tool:
Bitmap Font Generator VirtualBox was my friend.
As you can see on this picture the program has exactly the Raydium font alignments.
2. You have to install the fonts under Windows. (e. g. right-click on the TTF or FON file and 'Install...')
3. Select your favorite font and
disable UNICODE to get a greater canvas!
4. Now the ugly part, don't use the regular export to TGA function, since this will export an unusable file for Raydium (I was not able to get this working), we will take a picture instead.
5. Resize the window to get the canvas area 512x512 or higher, try to keep the 1:1 aspect ratio.
6. Take a screenshot and cut the canvas with your favorite image manipulation program. (e. g. The GIMP)
7. Invert the colors.
8. Fix the boxes not including a character of the font with black color.
9. Remove the alpha channel.
10. Set the image from RGB to grayscale.
11. Resize to 512x512 if necessary and test it with Raydium.
I hope this little "How-To" will help you to reach your goal.