Hi,
I can do this for you in Eagle CAD. Please note that the LM3S6432 chip uses a BGA package and so will be expensive to prototype/manufacture. If you prefer I can recommend the STM32F107VC which is a TQFP package, more RAM (64K), more Flash (256K), uses the same ARM Cortex M3 core, has all the same peripherals and is much cheaper to boot.
If you do go with the STM32F107VC then I can even provide you the complete software stack with FreeRTOS, LwIP TCP/IP stack and Web Server for a nominal price.
Please see my profile for a similar ethernet board.
Thanks & regards,
Rajiv