I myself have long had a passion for folding stilettos, both manual and automatic. They are my favorite type of knives.
If you are interested in single edged manual stilettos, Kissing Crane stilettos are single edged, the older ones were made in Italy by Angelo Campolin. Many people mistakenly believe they were made in Germany because the blades say "Germany" and "Rostfrei", but the reason they say those things is because Kissing Crane was a German company, the knives were made for a German company, and they were sold by a German company. Some time back however BudK bought Kissing Crane and started having the knives made in China. So if you want an Italian-made one you have to buy an older one. The older ones come in a variety of sizes, but I believe BudK only makes the 9" open length (8-3/4") size. So if you buy larger than that you are getting an Italian-made one. The steel is likely 420. Older KC stilettos can sometimes be found on the secondary market.
I own, and carried a Kissing Crane stiletto for many years.
Angelo Campolin also had his own line of manual folding stilettos made and sold under the name Falcon. These can sometimes be found on the secondary market.
But I would say that my favorite traditional-style manual folding stiletto is the Rite Edge brand. Single-edged blades. They measure almost 11", have stainless steel liners, solid stainless steel bolsters, and the bolsters are actually welded to the liners, this makes for a very solid and robust handle, which is unusual among traditional folding stilettos. They are made in China, and fit and finish is hit or miss. The blade steel is a mystery, but I found it to be quite capable for basic cutting tasks. I started out customizing Rite Edge stilettos before moving into making switchblades, converting them into one-hand openers (and sometimes also one-hand closers), as well as replacing handle scales. Below is a picture of a few, and a video. The reddish wood handles are the originals, but the thumb stud is my addition.
As for the knife in the video you posted, AKC (Automatic Knife Creations) no longer make such knives (the AKC brand is owned by the Campolins). The Campolins also used to produce and sell identical manual swing guard stilettos under their own name, but I don't believe they do anymore. There are a lot of fake "AKC" branded stilettos out there that are made in China.
As for modern style folding stilettos, as Deino mentioned, Cold Steel sells the Ti-Lite series (the Ti-Lite 6 being my all-time favorite knife). It is available in two sizes, three different handle materials (Zytel, aluminum, G10), and currently in three different steels- AUS8, AUS10, and s35vn. Based on torture test videos I've seen, I consider the Ti-Lite 6 to be the strongest folding stiletto available.
There is also the Al Mar Quicksilver Slimline stiletto, with D2 blade. I have no experience with those.
That's about all I can think of at the moment as far as manual folding stilettos. There are a lot of cheaper ones out there, like MTech, or "Godfather", but I'm very leery of really cheap liner lock folders, and I wouldn't bother with them.