Want bigger? Consider having a pianist perform. Bring in the baby grand and WOW, you have a sound that can not be replicated. If you've never seen a pianist playing classical...find one. Its just sublime. If you like the idea of totally unique sound and a performance, try an electric violin duo or ensemble.
Trying to think of a great way to give the band a break, but don't want that lull that always comes with it? Check out Drumadics : Y'all they are insane I tell you.