Is there a good guide to do this, and is it more economical/better than using one of those C= ones on amikit?
The 23-pin to VGA adapters (The silver boxy thing with the raised chickenlips logo) aren't too expensive, and have served me well in the pase, though if you want to wire your own, the pinouts for the Amiga RGB port and a VGA Monitor are @
http://pinouts.ru/Video/AmigaVideo_pinout.shtml and
http://pinouts.ru/Video/VGA15_pinout.shtml. Also, if you're looking for a DIY scandoubler to hook up a VGA monitor to an Amiga, those are a bit more complicated. Though I have a COCO external designed for an Atari (
http://www.miba51.com/CoCo_VGA_Adpater.html). This guy (Roy) makes them in his basement or something, and they work ok. They ARE 16-bit, though, while AGA and above is 24-bit output, this results in fewer colors to the monitor, and more noticably a green-shift on the image. (This can be adjusted for a bit if your monitor has RGB controls) One thing I like about it is it keeps the Amiga's output unmodified, so you can still get 15Khz output for PAL/NTSC out of the RF-Modulator or Composite port if you do any video work.