Firstly, you might need to consider why do you need one.

1) Are you a frequent typer working on iPad?
2) Are you a power user?
3) Do you love to carry and type or just use it while on desk at home?
4) Do you prefer it combined with your iPad or seperated?
5) How long is your typing session?

iPad Pro
If you looking for an easy carry and sleek keyboard case, Apple Smart Keyboard is your choice!
-Cons: Expensive, No backlit, Less key travel, No function keys

To solve the cons, you might get looking into Logitech Create Keyboard with all those function keys and backlit. It is RM599, RM99 cheaper!
-Cons: Heavy, bulky, makes portrait Apple Pencil writing difficult.

For all kind of iPads, I recommended and I am currently using Logitech K380 which only cost RM149.

Pros: Sleek design, Stable bluetooth connection, Multi devices, Function keys

K380 is a good keyboard for long duration typing! It featured a full size keyboard layout like the one on laptop. Good key travel gives you the sensation of typing! Just press the device switching button "1", "2", "3" allows you to switch between 3 devices assigned into the keyboard! The function keys are the perk for iOS user, exit to Home, Volume buttons, Keyboard toggle and media keys etc! It works like Magic Keyboard which cost RM429 but it has more features than Apple Magic Keyboard![attachmentid=8905876]