Get a sump. There are no hang-ons strong enough for a 120gal. Do not believe manufacturer recommendations. Anyone can say their skimmer will skim up to a 200gal tank to sell their product.
If you really don't want to put in the effort, than I guess the best hang-on for your tank would be a Deltec MCE 600.
IME, I have run quite a few different combinations of skimmers at the same time, both will skim. There will be enough nutrients in a 120gal for both skimmers, especially since a single Remora pro cannot efficiently skim a 120gal tank (unless there are no fish).
to run 2 of these skimmers you will have to have 2 big pumps like mag 3 in the display or a big pump branched out. Either way it will detract from the look of the reef.
I don't know about 200gals but that looks a lot better than the Deltec, Aqua C, or any other hang on. I like how on the Life-reef website, they refer to other hang on skimmers at "Toys"
The TurboFlotor Multi is a good skimmer. I'm using it on my 120 and it's doing the job well. I have it in my sump, but it can also be used as a HOB. Any hang on is going to mean a rather larg pump in the display tank.