Questions on Endpoint GUP

We have our main facility running our SEPM/SEP version 12.1 on a Windows Server 2008 R2.  We have 2 remote sites that have their own internal networks, and are currently connected to the main facility each using Point-to-Point T1 connections. All of our servers reside at the main facility, therefore all activity from the remote sites go to the main facility, either to access a server or gain internet access through our firewall.  We have 10 clients at each remote site and almost 200 at the main facility. One of our remote sites runs especially slow almost all morning on Monday mornings.  The network team has run an analysis on this multiple times and have found that a huge amount of traffic is going from the SEP server to various workstations.  I'm thinking that a GUP at the remote site is the way to go, since they would still be using up the bandwidth if I set them all up to update on their own.  First of all, does this sound like the best way to handle the situation?  Is the GUP required to have a Server OS, or would a Windows 7 PC suffice?  Any ideas are welcome.  Thanks!