This vest pattern is knit in a Garter stitch with a slip stitch and is very easy.
It also has darts in the fronts for a better fit than most vest patterns.
I knit it in Cyochin and Lanaloft because that is what I had on hand, but any Aran weight yarn will be beautiful.
I have suggested the Silk Garden and Silk Garden Solo in similar colors.
Take time to check your gauge.