Overloaded with acquired offices

I am an network admin. asst. with no time and just had a project dumped in my lap and I need HELP! My company just aquired 10 more remote sales offices in major cities with 12 users remotely performing 40% of thier work 60% of the time (sales). I currently have a RAS supporting 10 users (outside sales people)on a 1-800 line with a 8-modem hunt group. All remote users require access to internal databases and files. Support large file transfers between offices. Have a central administration point.
Any suggestions on how I can start to make this work for a reasonable amount so that all sales people have the same services and can all connect to the network at the same time.