Really it's the majority that is plate mount. It's much simpler to list the PCB mount for you to avoid then.
So here is a list of PCB mount boards you are not looking for that have no plate stock (though aftermarket plate is available for some):
Cherry G80 line, Vortex/KBC/KBT Poker/Pure/Race, Plum 96, Neo Zelia.
Pretty much anything else you will find has a plate.