Any of the 8bitdos will work. If you have an older one, you just need to update the firmware. I have the NES30 and SFC30 (the one Snorenado posted) models, but there's a newer model that looks even better:
(Image removed from quote.)
It has two sets of shoulder buttons on top. No idea if this is the case, but I wonder if those two smaller buttons on the face work as home and photo buttons when paired with the Switch?
They also have an arcade stick.
Also to note, the Hori left-joycon with real d-pad is out in Japan now, but it will only work with the console in handheld mode.