It doesn't matter as regards this. All the vendors know how to do it. Buy whatever you want based on your other criteria and preferences. For that matter, you're OK even if you get one without built-in Wi-Fi. Decent Wi-Fi antennas are available for $25 or so, often less, in both PCI card and USB dongle form factors. While most new laptops have it, if you come across a used one that's suitable otherwise you don't have to let this issue deter you from getting it.