Regarding vests, I just don't think it works with the cut at all. I did it once and I never wear the vest. Vests absolutely require full cut high waisted trousers, which Italian tailors seem allergic to.
So what they tend to do instead is cut the vest really long, a look I quite hate. And then their hip hugger pants really can't be worn with braces, so that means you need a belt under the vest, which also looks terrible.