Which one should I go for, as a photographer and graphic designer, iPad Mini or iPad 4?

This is my first iPad purchase (or about to), I have never owned a tablet. A photographer friend recently brought it to my attention that you can have an accessory for your iPad to connect a device to plug in your SD to your iPad, which makes photos viewing easy and a quick edit or two helps. I got interested because it would make it easier for me as a photographer to show clients the photos we took and from there, they can choose the photos - less hassle for me when I edit the photos.

Originally, I wanted to go for the mini but I've heard it's dpi isn't that great and it's not suited for editing? The price seems decent... The iPad 4 just breaks my har two. So, I hope you guys can help me decide 😟 Because not only am using this iPad for work-related, hobby/leisure use but I'll also use it for college.

Thank you!