If you don't want to spend the $$ then DaVinci Resolve is a great tool, too. And not just for grading, the newer versions (v14 is in beta) is a pretty robust complete solution, and it is quickly becoming as popular as Premiere and Final Cut Pro, it seems. I've dabbled with it, but I'm not a pro and I'm a Premiere Pro user otherwise so for now I'm sticking with Premiere.
But there are tons of youtube videos for DaVinci Resolve training.
Best part? The standalone version is free. The only caveat is there is a learning curve with any of these apps - but once you get over the hump you won't really be able to fathom using anything less powerful.
For Resolutions, the top 4K resolution is "actual" 4k, cinema 4k which is a 1:1.9 aspect ratio which is what you see at the movies. The next step down is "tv" 4k, or UHD, which is 4k in 16:9 aspect ratio. The 2.7k is also 16:9, there is no 1:1.9 2.7K.
If your laptop can't handle the 100mbps 4K its honestly doubtful that it will handle the 80mbps 2.7k any better. Either way you're really going to need to transcode or use proxy files to edit them away from a more powerful machine. FWIW I was a little overwhelmed at the proxy editing at first, but once I figured out the workflow I can't imagine doing it any other way. Even on my high end workstation I transcode and do most of my logging and editing on the proxy files. And Final Cut Pro, Premiere Pro, and DaVinci Resolve all natively support a proxy workflow. In Premiere, when I ingest the proxy files are now automatically created int he background, and there's a little toggle button right in the UI to click and toggle between proxy files or originals.