Looking for a good dual homing situation in Macomb County, MI

Hi - We currently have PSINet routing our CIDR block to us over a DSL connection. I'd like to become dual-homed (for reliability). Anyone know of a DSL provider that serves our area and also will route an address block that isn't one of their blocks? We operate an ORSC root server as well as several large TLDs and need the reliability of two connections.