JW - hope you're receiving email posts to replies, cause this is a slow response (never scrolled down the home page to see Hardware category)
JW -- I recommend Windows 2000 to help you with this UPS solution. While the literature and documentation makes comments regarding orderly shutdown "unattended" experience dictates otherwise. Having to start the ubiquitious (hey, what does that mean anywhay?) Microsoft operating systems after an unorderly shutdown is harrowing... The file recovery system review time is unpredictable....
Win2K allows for configuration of "support for UPS", so that you can manually program in autoshut down within xx-minutes of being notified of an (interrupt) event. At the same time, the UPS sends a recognized (prearranged) interrupt (event) to the operating system by means of a "port", which trips an IRC (interrupt code) and a utility program (provided by the UPS mfgr) is triggered.
Going through these steps exposes just how all these providers propose to work with the most popular operating systems. Actually seeing it done, especially when "trading software and active open positions are at risk" is a whole 'nother thing. Hence, you will want to rest greater assurance upon the "insurance of an UPS" if they can either deliniate what I have just advised. If their tech support says:
.. "it should", or
.."it says it can", or
.."its supposed to"...
then change vendors.
Cheers