I was going to suggest the other paper bus thread (
Paper Buses) but now I can see you've already been there.
It depends what specifically you're looking for - if it's a vehicle type you're after then a quick Google search such as "Optare Versa paper bus" should do the trick.
Also depends what your definition of a 'good' paperbus is, as some have the roof & offside included so you can assemble them while others have interior detail, panel gaps and shading. Or if you like repainting then there's the basic sort like the ones I've done that only have the nearside and flat areas to colour.
If you've exhausted the usual sources (Ron & Tom's blog, various Peter Fray nets floating around online etc) then there's a couple of places on Flickr such as Fraser Eagle and Pained by Michael who have buses, though these are just for looking at and not for editing. They are very nice though.