I'm sensing OP is getting a bit annoyed by our concerns. I'm sorry. I really can see how you like cats and want to get one and maybe you think we whine too much
however it doesn't seem like an ideal situation unless it was a life or death situation.
I think Lindapalm's idea is AWESOME. If you go to a shelter you get to spend time with cats, play with them, pet them, hold them they need it and you seem to be willing to give some wove. Maybe you could consider that instead.
P.S. Never leave a cat on a leash unsupervised it's reaaaally not a good idea. They can hang themselves, get entangled, all sort of stuff.