Most US-based broadband providers here provide the modems, so not a lot of people here have experience shopping for DSL modems or modem/router combos for that matter. I've never even heard of Billion. The VoIP thing also sounds good, too, but again, most VoIP providers here provide the hardware to plug your existing phone to the internet (like Vonage).
in Oz you ahve the choice the get one or pay 100$ and get a crappy one from the isp. I was looking at some buffelo and linksys ones, but they're just too expensive.