Im not familiar with your particular modem, but you basically need to do some kind of bridging or un-numbered mode. What this means is the verizon modem needs to pass the public ip info on through to your router. Essentially turning your modem into a converter box ... converting the signal from dsl phone line to ethernet ... then letting your linksys do the routing.
There are 2 ways to look at this:
1. The username/password (PPPoA or PPPoE) info can stay on the modem, but pass through public info all the way to your linksys router. Qwest modems call this unnumbered mode.
2. The username/password (PPPoA or PPPoE) info can be handled by your linksys by bridging the modem and entering the info into your linksys. Here's a link that shows how to do this with your modem: http://www.lava.net/support/Westell_...allation_Guide
Your best bet is to call Verizon tech support and explain to them what you're wanting to do and see if they can walk you through it.