OO is ideal for rolling stock.
However, for railway model buildings, I'd take a fig with you and look at some of the HO kits that are out there. If the doors are big enough, or if you don't mind a bit of compression, you'd be surprised at what looks right even if it's a bit smaller in scale. Industrial buildings are especially good for this.
You'll also find alot more and more affordable HO building kits in the USA as it's by far the most common scale here.