As part of the service, you may also get network management for associated facilities, security and other services. The contract may or may not include the cost of a router, system installation and integration, and training. Be thorough in evaluating providers. Ask for customer references. Although you can mix and match providers, the fewer you have, the less the finger pointing and the better intersite service may be.
Many providers offer network design, consulting and systems integration services.
Even so, you may want more, or different, facilities. There's a wealth of products from which to choose. To the extent you can, try to exercise MIS control over what gets selected. However, that doesn't mean they'll all have the requisite features or be equally easy to manage. Start by identifying what tasks your people want to do, and what platforms they're currently using.