There are some things you need to consider before you decide which knife to purchase. What are the restrictions in your area on concealed weapons, and will a CWP take care of said restrictions? Are you allowed to carry a double edge blade in your area (permit or not)? What type of clothing do you wear, and will it allow for you to carry your knife of choice easily?
Then you need to decide what you want your knife to do, and which would be suit your needs. Personally, I think carrying any type of throwing knife is a little.....for lack of a better term, Hollywood. I can't think if a situation where having a throwing knife will give you any sort of advantage in an attack. Further, if your assailant is running away and you decide to go Rambo on him and throw your knife at him then you have a whole new set of legal issues. So I guess what I'm asking is, why are you considering a throwing knife at all for personal protection? Just curious as to why you have made that choice.......
As for the site you listed, it seems to be pretty well laid out, but I don't know exactly what your wanting to know about it.
And as for recommendations, I personally tend to prefer to carry folding knives concealed. They are generally easier to conceal, have more practical uses outside of SD applications, and it's a heck of a lot easier to talk your way out of trouble with the law if they find one on you then if your carrying a double edge throwing knife. My exact knife tends to vary, but right now I'm carrying the Darrel Ralph Maxx-Q Tactical from Meyerco and the Boker Plus G4. SOG and Cold Steel make some good entry level SD knives as well. If your looking to get a little more expensive then I highly recommend looking at the Lone Wolf line. I have the T2 and really like it. It's a bit big for concealment though, but they do carry some smaller blades as well. If your going for a fixed blade then I would stay away from double edge blades, it's just too hard to convince a cop that you have only the best, most legal intentions in mind if they find it and start asking questions. Just my $0.02......
EDIT:
I forgot to mention one thing, as someone else here alluded to. Training is always the most important feature of any SD plan. While the knife is important, if you don't have a clue how to use it then it does you absolutely no good. Carry, deployment, grip, motions, ect must always be considered and you need to continually train with your knife of choice in order to be prepared for when you encounter a SHTF situation. But also realize that no amount of training (or the best knife in the world) will ever guarantee success. So don't think that just because you have a knife and have trained with it that you can walk into any situation and come out without a scratch, cause it's just not gonna happen.