How to choose the best pen tablet ?

I’m not a professional artist or anything but I’m pretty good with traditional sketching and inking. I’ve been planning to start a graphic novel and after a couple months of toying with the idea realized that the traditional medium won’t cut it for me.

I’m planning on buying a XP-Pen tablet and am very confused. I’m split between the new XP-Pen Star G640S pen tablet and the XP-Pen Artist 12 pen display. I have a HP Pavilion laptop with 15.6 display. I used to have a drawing tablet before (old wacom bamboo tablet) and I found myself struggling to draw, while looking at the computer screen.Does anyone else have the same problem or is it a matter of practice?

With xp-pen Artist 12 drawing monitor ( ) , I can simply just draw on the tablet screen, but I still don’t know whether it is worth buying something 6 times more than Star G640S ( ) ? Anyone have an experience on these tablets and is able to share with me?

Please guide me