Hi there
There is some that i used but can't remember the name or KUID of them, There highway signs with pointed ends that I used as route signs, they come in White, Blue, Green, Yellow, If I do remember right they were Dutch and the different colors were for highways, Public and Private roads.
There is other UK ones but not sure if there large enough for what you want but there name UK direction sign and the extra sign is UK direction post1
Will look up the Names for you and post tomorrow, atleast it will be easy to find now I have left a message
Hoping I can help
Tom