Can somebody suggest sliders that would be fitting for an equalizer?

I use J.River Media Center, but the full equalizer isn’t exposed in the API. I can however send HTTP commands like this:

That one sets the value of the 31.1 Hz slider to +25 %, which means 3 dB in this equalizer:

What I’m looking for is a slider version that I can configure so I have one per slider in the equalizer, which means 20, but isn’t so big that it won’t work on a phone or tablet screen. Preferably with vertical sliders, if possible. Since there is no feedback (at least I don’t think there is one, I have asked on the JRMC board) I guess I have to assume the value has gone through. That means that there can be no adjustments done to the equalizer outside of Hass, but that isn’t a big problem if the sliders in Hass work well. I just need to know they are syncronized. it would be nice to have the percentage or the dB value shown as a number as well, even if that isn’t a must. Does anybody have a suggestion about something that would fit the bill? I have looked around a bit, but not found something that is ticking my boxes.