For what function?? Are you planning on hiking, or just need something to carry it all in?

LowePro has a neat thing called the product finder that can help you!
www.lowepro.com
Tamrac has a wide selection, too.
www.tamrac.com

Now, all that being said, these sites can give you an idea of the different sizes & styles of bags. You will have to figure out what works for you!
Good hunting!!!