Just make sure you have lots of RAM and a decent SSD drive in the laptop or even a desktop All-in-one for the CAD software.
8 GB should be the minimum RAM you get. More the merrier with CAD. Most modern computers come with a decent video chipset that will handle the 2D of CAD just fine. I would not recommend a tablet for CAD. They will do it, but just not as smooth and fast.
That is straight from a engineer client of mine that does use both a tablet and a desktop. Tablet handles the smaller drawings just fine and is great for when he is on the job site. But when he has editing to do where he needs the entire drawing, his desktop is the way to go. He's not an RV'er, so his Desktop is a full tower with 64 GB of RAM, SSD drives and a couple of 30" screens. His home system is an iMac that he dual boots with Windows 7 and Mac OS when he really has to do something at home.
I'ev not seen an All-in-one without WiFi already included in recent years.
The other great thing about a Laptop instead is security. You can lock it away in a drawer or something.
There are some laptops that offer spectacular performance. The key is, as far as CAD goes, memory. Getting at least 8 GB, 16 GB would be better. SSD helps speed those loads up as well.