I have to agree regarding looks over originality.
I'm also a big fan of the plunger style seats. They fit straight on, look the same except the pillion section is much narrower and doesnt overhang the mudguard as much. They can also be picked up quite cheaply as they were often fitted to such things as plunger Bantams, the owners of which invariably decide to replace them with a sprung saddle .
Cheers,
Iain