After taking another look at the specs ...
1) The first
one I linked to has a nice web interface
. Lots of "advanced" features
2) The second
one I linked to is not on-line ... but is controlled via DTMF phone signals (and, hopefully, cell-phones); after three rings, apparently. It needs a dedicated phone line.
3) The Aviosys
units appear to be simpler (which is not always such a bad thing). Switched on or off via
email, for example. This
one looks nice.