With out the expensive machine for cutting? top of wedding cake I need a TML...should it even be fondant. The have to stand straight up somehow.
For the letters to stand up you're best to use gum paste also remember to insert your tooth pick while it is still soft to have a support to put in the cake. You can cut them out but what I see most people do is they shape a gum paste snake to the desired shape. I've done them in cookie pops, they only need 24hrs to dry and are sturdy.