I would not do a surface, the screens cannot be replaced easily.
we have gone through 6 of them in the lase 18 months.
my preference is a laptop with a minimum of 500 GB solid state drive, 8 GB ram minimum, Windows7 (cant get that any more), so windows 10.
install vmplayer and create virtual machines with 30-60GB drives.
install ab plc software on one vm, siemens on another (I have been told by an oem that ab and siemens don't play well together), scada software on another.
my personal home laptop is a Toshiba, 17 1/2" screen, 24GB ram, 1 TB solid state drive, vm player with multiple vm's for ab software, rsview, and wonderware.
At work, we use Dell latitude laptops. they have windows 7 pro on them.
james