Considering what you have already stated. I would get nothing from there until you have heard more about any of these products. I cannot read anything on that page. I see the pics but it doesn't tell me much at all. So if I was you, I would wait until someone else decides to be the guinea pig on these items. Just my 2 cents. I personally love my ES just the way it is now. I like what you have done to your ride already. Also our wheels look very similar. Mine are Maxxim Deadlines though. Like you said the red lines set them inline with the rest of the car
Ultra Racing is from my country, Malaysia. They are the largest mainstream manufacturer here for sway bars, chassis braces etc and are quite well-known in South East Asia. They do sell products for a large variety of cars and are priced quite well but I wouldn't consider them top-grade (or motorsport-centric) stuff. A lot of people here use them though. Just sharing what I know.
You can jack up the front end of the Elantra (behind the front wheel) and it lifts the rear end in almost completely in line with the front. No sag. This car doesn't really need chassis bracing IMO so I wouldn't buy any of it. At that level of stiffness, bolting on pieces of aluminum isn't going to do much (outside of lighten your wallet and give you a case of placebo). You'll need to start welding in pieces if you want an improvement.