Wide Area Network Design

I am attemping to design the following network:
Main Office: Albany, NY; 300 Users; Must Have VPN capabilities for 100 connections (Approx. 75 user with broadband and 25 still on dial-up)
Office 2: Chicago, IL; 100 Users
Office 3: Tampa, FL; 75 Users
Office 4: Los Angeles, CA; 150 Users

Heres is what I have come up with so far:
Albany will have an ATM connection due to the large amount of users.
The other remote offices will connect via frame realy due to the smaller amount of users.

Albany, NY
- Router being used will be the Cisco 7613
- The Dial-in users will dial in to a modem banks which are Lucent Portmaster 3 for VPN connectivity.
- All users will be running out of the 7613 router with LAN Ethernet Modules installed.

Chicago, IL
- Router being used will be the Cisco 7604
- All the users will be fed off of 3560 Switches for future expansion there will be 3 switches used.

Tampa, FL
- Router being used will be the Cisco 7604
- All users will be fed off of 2950 switches because of the smaller size they do not plan to expand this office much more or require extra technologies.

Los Angeles, CA
- Router being used will be the Cisco 3845
- All users will be fed off of four 3560 Cisco switches



Is this an acceptable design for the network I am trying to implement?
Please suggest any changes that will enhance this designs performance and overall setup.

Thanks in advance!