Personally, I wouldn't have any computer less then 16GB of RAM now (not even my minipc in the guestroom with Atom processor has less then 16GB in it). I'm not one of those that believes in overloading RAM, video memory etc, I believe more in matching type of ram and video card to the application. But if your only resource intensive program is Flexi for cut vinyl only, then that does change things up compared to a true workstation computer that I would normally suggest.
If it's perpetually connected to the internet, I wouldn't get any version of Win 10 that doesn't allow you to defer updates. I'm not against updates in of themselves when it's a computer that's connected to an outside network (although not something I suggest period for a true production rig), but having a version of Windows that allows for MS to roll out updates when they think they are ready is no bueno. That makes Windows more of a rolling release beta OS more then anything. My dad has had a horrible experience with Win 10 updates and he doesn't run esoteric software like some of us might and in this case, and I would consider Flexi to be one of those.