as others have pointed out, JianPu choices are indeed limited. Most of them are lacking in features, or look really terrible (which can be distracting when playing). There was promise in 2011 when someone wanted to bring about JianPu support for MuseScore, but sadly it never came to reality. Hopefully in the future there'll be more widespread support for JianPu, but personally I highly doubt it - many professional Chinese emsembles have taken to Staff notation so there is a lack of demand for proprietary WYSIWYG editors (IMHO).
Since you're scribing for erhu, Simp-Erhu would be ideal because the formatting is acceptable and the symbols representing instrument techniques are available. Of course, as aforementioned, this comes with the downside of needing MS Word.
Personally, I'd scribe JianPu by hand myself after printing out templates. This method is much much faster than any editor to my knowledge (since it requires no fiddling and is WYSIWYG), and is much easier to make legible than Staff notation.
For templates, it varies from person to person; I've seen a myriad ranging form foolscap to grids made using tables in MS Word (my personal favourite; attached) to dotted lines.
I do speak (and write) Mandarin Chinese, so I could help you with editors mentioned by others if you'd like. Personally I'd rather choose to scribe them by hand simply because this is a case where it's easier to do so (as compared to with Staff notation where WYSIWYG editors are aplenty and easy to use AND yeilds great results).