Yeah, the special Switch keyboards I've seen are too small to type comfortably.
About USB C: Does the Switch accept it if you plug an USB-C keyboard directly into its port? It probably does, but to use it when docked, you want to stick to USB-A and use an adapter when in mobile/tabletop mode.
I have this one: http://www.rapoo.com/product/539
I would not recommend it too much.
Good about it:
full sized cursor keys.
can also connect to other devices via Bluetooth, three separate ones even. As long as USB and Bluetooth are around, I'll never buy another wireless keyboard without this feature. Well, two Bluetooth devices would do.
Bad:
the cursor keys are stuffed in right between other keys and are hard to hit
the keys are a bit wobbly and the initial touch is too soft
Not the keyboard's fault, but still bad:
on the Switch, the number block can't be used in the alternative mode where it has the page up/down keys
the wireless connection is not 100% reliable for our TV to couch distance (about 3 m)
So most of the time I use a full sized wireless Dell keyboard. Which I also can't recommend because I can't find it online. And its Bluetooth sync behavior is abysmal.
Soo.. Steve's recommendation looks good if you don't need Bluetooth and can arrange yourself with the half height cursor keys (you better should, they seem to be the norm these days). Could have saved us all a lot of time if I just had said that :)