So... After trying different ones and researching I decided to order the one I've never seen/tried "in person": Browsing Store - Woof Ergo Zip Adult Body Protector
(+ free shipping + additional 10% off). The reason behind I didn't like CO and Flex Rider I tried in local Dover, and Airowear is too pricey (yes, I know you can order it cheaper in UK, but I'm terribly bad on taking measurements, and it's too expensive to return it
I tried it on twice so far (as I rarely do some little jumping), but I was quite impressed with the comfort it offers (unlike some others I tried) and the fact you don't look like a box on legs.
And it's Level 3 certified (the highest).
Here are some (not the greatest quality) pics...