The Westell 327w doesn't have support for WPA2-PSK Security, though I have seen mention of a few 327w units being around that support WPA2. It could be possible though, that those units were of a different model or build than the ones Verizon handed out.
Anyhow, if it isn't listed in the firmware under the Wireless Settings (Basic or Advanced), it won't support it. Verizon's Westell 7500s don't support WPA2 either, however the Verizon FiOS routers made by ActionTec and Westell do.
On the DSL, if you want to use WPA2 security I would suggest using a basic modem and your own router and going from there. Otherwise, use WPA-PSK TKIP with a strong key.