Eth module long time stability (not to hang)

[Tehnicni]

Halloo for a 1st time

Which Arduino Eth module to use to get best long time stability (not to hang) which is most important for my system?
I'm also worried about lightning strike and because of that I'm thinking to use POEth (12V from Eth Switch through 2 unused pair in UTP cable)

About my system
I'm working on idea to build home automatisation system with 6 arduino (mainly Mega) around the house and uATX PC http://www.pcengines.ch/alix1d.htm with LabView 8.2.
I'm in doubt which communication to use, Eth or RS485. Last one is rock stable I thing.

[Tehnicni]

I will use Ethernet, which IC is better ENC28J60 or W5100.
It's these OK , they have 3.3V power IC http://www.dx.com/p/enc28j60-spi-rj45-ethernet-scm-development-board-module-deep-blue-320160#.VOiAunPnjqA

Is this true "ENC28J60 doesn't support TCP offloading, which means your code needs a plugin library which makes the sketch pretty big." http://forum.arduino.cc/index.php?topic=264327.0
And what does it mean more load for Arduino uProc?

And also: "ENC28J60 does only Ethernet layer and W5100 implements up to socket layer" http://forum.arduino.cc/index.php?topic=56057.30

[chuyrg]

I solved this by resetting the module every once in a while, using the reset pin on the enc28j60, just need to send a digital write with a low value, and then a digital write in high, after doing this, you might want to use the begin function again, doing this, i've had the module last for 2 days with no hangs.