It all depends on the outfit you are wearing for example to my eye anyway a bow tie would not look right with the following


and a 4 in hand or cravat would not look right with this


It all depends on the formality of the event and the rest of your outfit. One word of advise if you are going to wear a bow tie then wear one that you have to tie yourself, in the long run they look far superior.

As for the cravat the closest thing I have is the Ruche tie and I only wore that once