Mike: You shouldn't need support for the router. I have one and it's plug and play. People here can walk you through anything. I use mine for cable, not DSL, but it should be the same story.
Mine is 100Mbps. Don't know if they have 1000Mbps as of this date. or if any do. If you have multiple Gigabit Ethernet devices, it could be a bottleneck to have a 100Mbps router.
They're cheap so if it breaks, easy to replace. I like frequent updates to the firmware for enhancements and fixes - they keep up with tech changes and trends. There is lots of help on the internet and the linksys web site is pretty good with a fair amount of support info.
I have a router from http://www.macsense.com/ the XRouter Pro (MIH-130/A), which is essentially the same thing as a linksys but my firmware hasn't been updated since 10/31/02 and that's not because its perfect...