This is a rather old post, but just had to answar.
If you have a APC ups why not use the APC software PowerChute Business Edition.
It have a linux rpm Agent with its own web interface, easy to manage and deteced my old smart UPS automaticly.
I had som problems with apcupsd that put my server in a reboot loop bacause of a faulty cable.
They do not have server consolle so you need a windows computer, if you have more computers connected.
You can then install a client on alle other windows computers that you need smooth shutdown on.
Realy nice web interface and gives alot of information, the server also have the posebility to shedule battery check, do runtime calibration, logs the power consuption and gives you a price estimate.....
Realy nice and free.