Two remote, active mirrors?

Just found the site, I hope to call this one my new home!

Here’s the situation:

I have 6 offices I need to network together, for purpose of ease, we’ll label them
1,2,3,4,5,6 lol

1 is the main server we have now,
and 1-3 is in the Southern US,
while 4-6 is in the Northern US.

Instead of making all the traffic go to #1, is there a way I can make a mirror server at #4,
and have 4-6 grab (files, email, data) off there, while 1-3 use #1?

Applications:
Exchange
Sharepoint
ACT! (kinda like Quickbooks)
(and tons of random files)

Thanks in advance!