You may also want to check out the columns part of moune999's Torrox set here. It's a huge, multi-upload set, and doesn't specifically have beams, but I thought the columns were relevant enough to link.
And then there's Raynuss' Patio Set. Again, not a lot of beams, and it is more for outdoors, but, depending on what you want to do, you may get some use out of it. (Direct link because Raynuss' blog is gone; I attached the preview pictures I had so that someone can see the full set and decide before they download if they want it.)
"May the sunlight find you, thy days be long, thy winters kind, thy roots be strong." -Grand Oak Tree, DAO