Kanex offers the Sydnee, an integrated desktop station that docks up to four iPads with the cables neatly concealed. You could then plug the Sydnee into your computer's USB port to sync and charge.
If you need to support a lot more than four iPads, check out the Tablet Charging Cabinet and Tablet Charging Cart from Anthro. They can support 20 to 40 tablets and keep them under lock and key, while charging. You can manage a lot of tablets in a small and secure footprint, which makes their solutions great for schools.
You might remember Anthro from their whimsical ads for their very sturdy desks and tablets. Anthro proudly makes all of their products in the USA and the tablet cart and cabinet are no exception.