1) The best solution would be to physically make a wire between two sites. Not sure it's possible with the wires but you'll have to ask an expert of a company that do WAN network cabling. This solution will cost you a lot of $$ for one shot deal.
2) You can try a private T1 or private ADSL between both sites. This will have the advantage of costing nothing to start but a cost a punch per month. Private T1 between both sites will be like having a wire between both sites but at 1.5 Mbs. This solution doesn't require a VPN that lower transfers speed with encryption and etc.
3) At worse, public ADSL or public T1. This solution requires a VPN to be created across the Internet, your bandwidth depend on your Internet speed and you'll share your bandwidth with other service.