waistcoat ideas

For my October wedding, I am wearing a 3 button single breasted charcoal-grey suit. I bought it at Brooks a month or so ago, and I'm pretty sure it's this one:

https://www.brooksbrothers.com/IWCa...ection_Id=418&Product_Id=830633&Parent_Id=216

My fiancee wants me to wear a waistcoat. Does a waistcoat work with the 3 button? I think I'm wearing a burgundy necktie (or some other autumn colo). Any ideas as to what style/color? Where to get one? Thanks.