I think you should call Lantern & Scroll (www.lanternandscroll.com or find them on Facebook) they are awesome to work with and reasonably priced. I recently bought these for our home. They might work for yours. But they can help you better. Cheers!

Custom?

I would stay traditional in the lantern style but go really big, you have the room and probably in black finish which will keep the classic look of your home.


here is the three light version which is bigger:
http://www.ballarddesigns.com/concord-3-light-outdoor-sconce/outdoor-lighting/outdoor-sconces/204092?isCrossSell=true&strategy=41

I'd look for a traditional lantern that is updated to give it a more modern look, such as the ones below.
Size wise, I think something in the 18-22" height range would work well for your house. But sometimes a shorter fixture will work if it is wide. It's the overall heft of the fixture that comes into play.
Carolyn Albert-Kincl, ASID
sconces

Check out Carolina Lanterns - and GO large scale. If you can do Gas - Gas lit lanterns would be stunning!