There are pretty much 2 choices for linux when it comes to adsl modems, a bad one and a good one.
The bad one is the 3com home connect, which used to be the only modem allowing the external IP on an internal interface. This is essential if you want to do your own NAT/firewalling/logging. Logging facilities even at expensive (1000+) modems, like the M1122, are lousy. IIRC there were some problems with this modem, like dealing with line noise. It was never an excellent choice. It's also now dead, even if I found one still in a shop I wouldn't get it, support is no longer existant, future bug fixes a thing of the past. The good one is the Alcatel Speedtouch Pro (the Home lacks the hub and some router functions I think and is only fractionally, if any, cheaper). There were no troubles yet reported on the adsl list. Everything else plain sucks, like doesn't have a linux driver, or doesn't allow running servers (lack of pinholing) or similar interesting things. Alternatively, get Telstra/Saturn, they give you a modem for effectively $7/month, which will obviously work on their network and works well with linux as it requires no linux drivers. The (minor) downside is you will have to provide your own NAT/firewall box, if you have your own linux firewall box already you're set. (Same with the alcatel home btw.) Volker
