I'm guessing RoadRunner is a high-speed connection. I've heard of it, but don't remember if it's cable or not.
Anyway, 802.11b has a max rate of 11Mbit/s and 802.11g has a max rate of 54Mbit/s. I would imagine the g router would be able to help you out.
I have a g router and am happy with the speed, but have never used a b version so I can't comment on a comparison.
(info from
wikipedia )