I live in hurricane alley as well as the severe thunderstorm capital of the world, so what you hear from me may not be necessary for you, but here's what I have and why, and I never miss a tick:
60 amps 120vac (3x20 amp circuits) of power behind my trading desk.
One circuit is dedicated to the primary trading system tower w/ dedicated UPS sized higher then the power supply (in watts) in the tower. It has a 2 hour runtime and I need every bit of that 2 hours.
Another circuit for monitors with dedicated UPS sized higher then the aggregate wattage of all the monitors (I use 42" lcd tv's for monitors). 2 hour runtime.
Another circuit for everything else at the desk which includes
Dell desktop for e-mail, backup trading, web surfing, photoshop, autocad, etc.
Laptop (not normally on)
Printers
Fax
Phone system
etc.
With a dedicated UPS for that circuit as well w/ 2 hour runtime.
In sizing your UPS system(s) consider the following:
1. What is the likeliness of an outage in your area?
2. What downside risk exists for an outage at any given time? (If you're trading heavy futures in a volatile market a greater investment in UPS is warranted vs. trading low beta stocks in an IRA).
3. What timeframe do you expect an outage to last?
4. Do you have lightning in your area and how much; what damage will result from a lightning strike if you don't have the protection in place?
5. What is the aggregate (total) wattage of all devices on that circuit and how long do you want (need) those devices to run (how long will the power be out?)
I found Newegg to be the best source for UPS systems.
I also have 2 generators (13kw) and even a UPS on my bedroom alarm clock; that's how serious of an issue it is here. Not only is outage an issue but also the lighning protection attained by having UPS systems all over the place.
I even have redundancy in my data connection. Primary is cable modem and backup is wireless broadband.
During volatile markets my systems (and I) run 24/7. During normal market volatility they run about 15 hours/ day.
Feel free to ask any questions you have after reading this.
M.