Here’s something for RMVXA users. It’s additional resources for the built-in generator to create your own charsets. The site can be found here. It’s been Google-translated from its original Japanese. I’ve not been able to test this out, but by all accounts it looks awesome!
You can download individual parts or all of them at once. Caveat: You might have to rename the resources, otherwise there’s a chance that the defaults will be overwritten.