Finding someone compatible, in the right age range and close by seems futile. That's why I M open to webcam partners.
It's not for me. For a start, it often sounds like online dating. Your post, for instance: I don't particularly see what's massively relevant in compatability other than you both seriously want to die and relatively soon. If that's the case, I don't see what matters much about age or whether your star signs align. You'll both be dead soon enough. I'm not having a pop you or saying it's wrong, it's just not something I can relate to.
Then there's the issue of you both going through with it. SI can kick in and one of you backs out at the last minute. Happens A LOT from what I've read on the subject. Could the survivor be potentially charged with assisted suicide? Depends on the jurisdiction probably and you probably should research what the law says on that where you live or where you plan on going through with it. Also imagine the distress watching someone else die may cause you.
Then there's the fact this other person is a stranger and you only know what they choose to tell you about them. The person who actually turns up at the folorn motel of destiny may well turn out to be quite different to what you were expecting. A vulnerable group like suicidal people is naturally going to attract exploitive people to take advantage of them in whatever way they see fit, whether that's financially, sexually, sadistically or a combination of awful motives.
If you want to go down this path then good luck but please be as careful as you reasonably can. Don't ignore instincts. If something feels off about them, there's a good change there actually is.
Good luck and all the best to you.