rs232 to ethernet

We have a Serial device with 9600 Baudrate ,now we
are planning to provide a TCP/IP connectivity to that device. Through my
search i came across this [
http://www.rabbitsemiconductor.com/products/Serial_to_Ethernet_Kit/index
.shtml] and Digi Connect SP but i could not find and development kit for Digi products;-)

  1. How much its gonna cost for finished product ? or say what will be the addtional cost with Digi SP?

  2. Do we have any option for TDIClient for your dvice? yes, i mean NDIS (Network Driver Interface Specification) driver for windows so we would
    be manipulating it from “NetWork COnnections” [Microsoft Windows OSs].

ali