Lots of the upper end of new laptops come without a DVD drive. There definitely are stand alone DVD drives which you can just plug in with a USB cable. I'm sure your new Sager has USB 3.0, so you should look for a USB 3.0 exterior DVD drive. You can get Blu-Ray too. One thing you may need to do is to use one of these exterior drives with your laptop plugged in. It depends on how much of a power draw they are.
Just go to Newegg or Amazon and do a search for exterior DVD drives.