Even if you don't want to do any serious lacing, you'll still want boning and a fairly stout fabric base. I'd recommend working from a corset pattern instead of a vest pattern. A corset pattern will give you a design that won't warp when under tension, unlike a vest, which is usually somewhat loose-fitting and will get all sorts of strange when you try to give it a full lacing. Do a mockup of the pattern to get the degree of snugness you want around the body, then draft shoulders and lapels off of the corset's pattern. In the end, you'll end up with two layers of fabric-- a corset, with lacing and front busk, connected to a fitted vest, with real front buttons and lacing up the back. The two layers would be joined at the center back, and share the same grommets and lacing, but the fabric layers would be separate, so the 'vest' can lay smoothly, with flat buttons and the slightest bit of ease, while the corset gives the needed support.
You could also do something like this: http://www.damseldress.com/store/display/2074/43/corsair
Front lacing with a solid back, instead of busk + back lacing. It looks less like an actual vest that the idea I posted above, but it's a lot simpler. You wouldn't have to fool around with getting the center back of the collar to work with your lacing panel, and there would be about half as many layers of fabric to deal with.