|Your question is just too vague.|
In order to give you a decent response we'd need to know the approximate size of your network including details like, number of geographical locations, remote sites (if any) in each geographical location, number of users per site/location.
How do your sites and locations interconnect, or how would you like them connected........and that of course is providing you have multiple locations/sites.
Will you be having a lot of outward facing servers?
Will you have a data center?
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.