I am pretty confident in guessing that the Enfora module does NOT support EDGE, as although EDGE had been a GSM add-on for some time it really hasn't gained much traction.
If you really want 3G speeds you're going to have to tether your zaurus to a mobile phone using USB or bluetooth. Or, if you live in USA, there's lots of coffee shops around with free wifi, or even go to Starbucks monthly to use $5 and get free ATT wifi!