Network Interface solution

I am looking for a microcontroller with the attributes listed below. It is for a network interface that will be interfacing with only one digital or analog I/O. It is desirable use a battery for powering the device. It will be sending the value of the I/O along with a date/time stamp. A few microchip solutions have been listed below, but I would be interested it there is a better solution.

Any input would be appreciated.

- Ethernet

- 8-bit or less

- Low power consumption (Battery, Power over Ethernet)

- Small

- Inexpensive

- Less than 4 A/D channels

- Minimal 8 to 16 I/O's

PIC10F200

PIC12F675

PIC12F683

PIC16F676