I am using Covad's dsl (1.2mb download speed with 256k upload speed) with 5 ip addresses for $80 a month($70 a month with 1 ip address is available). I have not experience any outages. It has been very reliable. Customer service is better than bellsouth.
Bellsouth has a lower speed dsl service for about $30 a month ... that should be good enough for trading.
I have a spare bellsouth modem/router for $30 (save yourself the bellsouth surcharge)