I'm going to put down my perspective and preconceptions concerning this. If I am wrong, feel free to educate my ignorance.
My understanding is roughly half of graphic designers can't actually freehand sketch well at all. I actually can really well. However, the things I would be digipainting are easy compared to something like the works of Albert Bierstadt. I would be doing logos with word art for tshirts, hats, stickers, etc.
A Surface Pro has Adobe Photoshop, all of its features, and a touchscreen. It's the better program, you don't really need to know how to draw to use it, but its extremely helpful. It has a touchscreen for digipainting if I want the option.
An iPad has procreate and its rather intuitive if you can just draw everything. Another nice thing is you don't need to worry about copyright laws if you drew it yourself unless somebody else already created it I.E. Pokemon, Scooby-Do, etc.
A Wacom 27 is out of my price range, but a 24 might not be, and a 16 is not.
I know what to do if I go the surface pro route.
No idea on the Wacoms, but I prefer mobility. I also don't want to tether tablets to my gaming rig. Again, I'm not digipainting anything insane.
As for the iPad. I'm assuming I do not need a Pro and that an Air is the best route? Is the regular iPad good enough? Are ipads more accurate than surface pros?