Of course a second question - Lightining

I see the option for a lightining counter. Is this specific to a brand or is there something that any station can use, including Davis.

The only one I can think of is Boltek, and that is a bit expensive for me now.

Check out this thread.
http://weather-watch.com/phpBB2/viewtopic.php?t=215

yup, anyone can add a dallas 1 wire lightning counter, but you need a spare com port
but now you can also use a labjack with another lightning counter, and the labjack is USB (i am still to resolve the lightning gif not uploading though)