If you really are into modern esoteric graphics cards, try getting one of the MooreThreads graphics cards. Especially since the makers are patriotically OBLIGATED to keep pumping out GPUs and support because it's all part of China's deglobalization charade.
About PC-98 - only really old models have just RGBI video, most of them can output analog RGB at 24KHz, and some later models even have a 31Khz option so they're usable with regular VGA CRTs, you can potentially use one outside of Japan without finding a unicorn monitor.
Oh yes, it's much more the PC88 that I'm interested in - and I believe those switched to analog fairly early as well, but I wanted to be able to use the really early models in a pinch. I also realized on the drive home that this supports all the frequencies necessary to run my x68000 once I fix the PSU!
