BTW, padding is not black magic. It's nothing but basic physics. The fundamental way it works is to reduce the force / unit area, by increasing area, or decreasing force. The expensive brand names mean nothing.
It does this one or both of two ways:
1. It spreads out the impact over a greater surface area.
2. It cushion the impact, by squishing down gradually (with resistance) to absorb the impact over a greater distance, which reduces force.
Gel and liquid filled pads only do #1. The gel or liquid moves around until the pad touches a greater area of your body.
Foam filled pads do both. Initially, they do #2 - but, as they deform, more and more of your body comes in contact with the foam, so the area increases as well.
(Hard shell pads, like you see on some Rollerblade knee and helmet pads, or helmets, are more complex. They mainly work by doing #1. In some cases, they also are shaped to keep the impact away from the most vulnerable bone, like right at the knee or elbow. But the good ones also use compressible padding underneath to do #2. Probably overkill for your purpose, and very obvious in appearance as well.)
(All padding also tends to reduce skin abrasion, by interposing something between your skin and the object, so, for example, the ice can't slide against or scratch your skin. Probably not important if it is already under clothing.)
I suggest you buy a cheap flat foam camping pad like
https://www.walmart.com/ip/Ozark-Trail-Blue-Camp-Pad/634956813. I've been using one to make insoles in athletic shoes and skates, for fit and to absorb impact. Works very well. (It mats down over the course of a few months, and needs to be replaced - but I doubt you will fall often enough for that to happen.)
Try it - hit your knees or hips hard through it. (I just tried it.) I think you will find that nothing is hurt or bruises. That tells me that it has about the right consistency, thickness, and degree of compressibility.
So cut up pieces to fit where you need them, and slip it under (or over) clothing. A few stitches with a needle and thread will hold it in place. (I would avoid fabric glue, because if you ever want to remove it, stitches are easier to remove.) It is possible that in certain places, like your hip, you don't need to sew - the shape of what is around it won't let it move. Maybe you could do that around your knee and elbow too - if you use a scissors to shape the pad a little to be concave and fit against your knee or elbow.
If you do want to be discrete - that would be done by feathering (thinning) the edges, so there is no obvious boundary under your clothing where the padding ends. (You can thin it with a scissors.)
(Of course, no padding is going to look exactly like skin, muscle and bone. When you wear tight fitting clothing, you can see the movement of these things under the clothing. For example, you can see which muscles contract.)
Simple, cheap, removable, and designed to be skin-safe. (Though, as with anything that goes against your skin, you might be allergic - so test it.) And you can adapt it to the size and shape of the body parts you want to protect. I suspect it will be better than anything you can buy.
Unless - if you wear translucent clothing over it, you might want padding whose color matches your skin. Maybe you could spray paint it to match - or maybe you would be better off with skin tone padding like you selected.
But it does sound like money is burning a hole in your wallet, and wants to be spent on something more expensive. I suspect any of the things you selected would do about or almost as well as a cut up camping pad. (Note: I've tried gel filled insoles in shoes - didn't work all that well. So I'm not sure how well the gel-padding will work. OTOH, some people in this forum have used gel padding at the tops of shoes.) Like I said, it's just basic physics; they will probably work too. So go ahead if that's what you want.