"What bridge do you reccomend" is a common question I get sent, usually followed by "for a Goodtime/Gold Tone/Generic Amazon banjo".
"Modern banjos", in my opinion, are unsuited for nylon strings. There are two (and perhaps a third) reasons for this. The first is the way necks are set with back angle. The second are the large frets. The third (and less crucial) is the gear tuners.
The current banjo was designed around wire strings and plectrum playing. Adding back angle to the neck allows for using a taller bridge with low action. The taller bridge is used for plectrum clearance (so that one does not scrape the head), the lower action is due to the non elastic wire strings requiring less area to vibrate. Along with this, smaller frets are usually an advantage with nylon strings.
It would be very little trouble for banjo makers to build banjos for nylon strings. These two changes (with the third being using friction pegs) is all that would be needed. But no current maker of "beginner banjos" is doing this that I know of. I proposed this to Deering and even offered to consult them for free but Janet said that they "have never been asked for such a setup"-- perhaps people should start asking.
My Focus is on "classic era banjos". As such, I will only be offering 1/2" tall bridges.
My answer is that I have no recommendation and do not recommend my bridges for modern banjos. Messages sent to me asking this question will go unanswered.
If enough of us demand correctly built banjos for nylon strings from these makers they will start to make them. Until that time, my focus will be on banjos built for gut strings from about 1870 to just before WW2. I would press banjo makers about this but I only play older banjos built in the time when gut was the way.
The correct setup for nylon strings has what would be considered "high" action by "modern standards". At the 12th fret or position, the action should be 3/16" to as high as 1/4". The neck should be set at zero degrees and flat or level with the head. With a 1/2" tall bridge you will get plenty of clearance to avoid buzzing. The resulting action height will vary depending on scale length.
