The VG20x are nice because you can use them as a full blown router (VPN, IGP, etc).
I think you'll have more cost per port using a VIC3 rather than VG204. Their capabilities will be equal, as opposed to when the ATAs were in use.
The ATAs are on their way out, and I think you'll find the VG20x to be an easier product to use and it will work better with faxes/modems. The ATAs don't have great fax/modem support where the VG20x will have T38 support and modem support.
For the locations with 15+ devices it may be worth looking into the VG224 as well, depending on usage.
-nick