I'm in the middle of making my Jango vest out of charcoal gray vinyl. I couldn't find a pattern either what I would reccomend (and what I did) was find a shirt that you like the fit then trace that out for your pattern. So far it's looking pretty good here. I'll post pics tomorrow.
P.S. I'm the 100th reply to this post..don't I win a Tennessee Tuxedo lunchbox or something?