They are selling them everywhere! But I haven't seen them anywhere on the streets (at least not where I live...). Probably because they make your legs look twice as big. I've Googled some ways to combine them I noticed some girls are really pulling them off well but others just don't... :s So before I walk the door out I just want to check if I look okay in them? Or do I look kinda ridiculous in them? link
Your legs look great in them. You definitely have the body to look good in them but I think I'd pair it with a different shirt. There's something about that entire outfit that is not working for me. Perhaps if the shirt was longer it might have looked better.
You're skinny enough to pull it off but I think you should go for a plainer white tshirt that's just a bit longer so it covers more of your crotch lol so the focus is on the leggings and if possible a more cropped black jacket