Normally this just works under Linux. If you want the official NVIDIA driver for the 740m you'll have to download it and install it, but that shouldn't be too hard and the included drivers are usually good enough for casual use.
Never-the-less, I've sometimes had trouble with Linux on cutting edge machines. It is well known that sometimes manufacturers change hardware without changing model numbers, so the only way to be absolutely sure Linux will work is to try it. One of the advantages of many Linux distros is that you can quickly try it out with a LiveCD - no need to install. If they'll let you pop in an boot from an Ubuntu Live-CD before you buy then you'll be able to quickly figure out what works. Apart from the GPU and wireless, check that the machine suspends/resumes properly when you close/open the lid. Also check any special hardware, such as a touch screens etc.
If there isn't any OS or data on the harddisk that you want to preserve, installing Linux can be almost as trivial as pressing "next" 11 times. Even if you somehow get stuck, you can browse the internet while installing, so there should be no need to "do your homework" prior to installation.
The article on Wine you mention is still current, but compatibility with the games you want is likely to be a larger issue than problems during installation. As noted by Matthew, you can check your favourite games against the Wine application compatibility database.