Is this true that VPN with MPLS requires a dedicated lease line and the lease line cannot be shared for other devices such as Internet access for surfing purposes?
There may be services from an ISP that impose that restriction. However, there is no inherent restriction in MPLS that it requires a dedicated leased line. As a matter of fact, one can say that one of the purposes of MPLS is to enable a "virtual" leased line type of network connection over a switched (public or private) network. Indeed, MPLS has been compared to VLAN technology and is known as the VLAN on the service provider backbone.
Given this fact it is quite easy to find services from ISPs that will provide you with VPN for corporate traffic and Internet access for Web and other traffic. I would recommend choosing a service provider that provides the flexibility, security and extended services for your corporate needs.