I just picked up an iPad Mini and I am going for a jisoncase vintage cover. I have had jisoncase covers before and the leather is really nice, and the case is very low profile while offering all the protection you would want.
https://www.amazon.com/Jisoncase-Le...9249782&sr=8-1&keywords=jisoncase+ipad+mini+4
I have looked into Zagg Slimbook as probably the best keyboard out there. It has a bad reputation because of cracking of the case, but based on my research they have updated the cases to prevent this from occurring again.
https://www.amazon.com/ZAGG-Ultrath...815&sr=8-1&keywords=zagg+slimbook+ipad+mini+4
Right now I use a stowaway bluetooth keyboard which opens to 92% size of a full size keyboard. Has excellent travel and a stand for me to put the mini on. It's the thinkoutside, or igo, branded keyboards that are no longer made, but it's the best for quick, close to real life typing. There are new ones out there like this - I think microsoft has one, but I love this stowaway kb.
https://www.amazon.com/Stowaway-Ultra-Slim-Bluetooth-Blackberry-Handhelds/dp/B0002OKCXE