My house is pretty old (~60 years, I think?), and has all sorts of problems. One of the big problems is that the 1.5-story house (which basically means that it's a 2-story with a smaller upstairs than downstairs) has a single A/C unit. This, in conjunction with having the A/C controller downstairs, makes everything upstairs much warmer in comparison. (I live in Texas, so it can get really hot around here.) This, coupled with the fact that I have a lot of computer equipment sitting in one room, makes that room really, really hot.
So, to make sure my components don't fry to death (and to keep a livable temperature in that room), I use a portable A/C unit in the office to keep things cooled. But with the electrical wiring and circuit breakers in the house being so old, the room consumes too much power for the breakers to handle, and each time the portable A/C turns on, the room electricity has a noticeable "skip". (As in the lights flicker for a fraction of a second, etc.) It's not a complete outage, as I have some cheaper stuff hooked up without a UPS that don't get power cycled, but with the light flickering and all, I'm thinking that it can't be good for computers (and electronics in general).
Even besides this room having a problem with the portable A/C, the house's elec. wiring in general seems to have a problem. The breakers will trip around once every month or two from various causes (heavy usage in the kitchen, for example), and the power goes out due to lightning a little too frequently for my taste as well.
So to protect my little toys, I invested in the nicest UPS that I could afford at the time. It's served me pretty well. I see it click on for short periods of time a couple of times per week or so.
I think you'd be better off spending the money on getting your house fixed. This would not only be safer for your computer but also safer for you!
When you say that lighting strikes frequently cause trips then this makes me think of earthing issues. I know in the US you have strange/dangerous ideas on what constitutes good earth wiring with all kinds of wierd things like using the plumbing of the house as the earth. I would first test the earth continuity between electrical sockets. Take a multimeter and a pair of IEC leads to measure the resistence across earths. I get around 1A here between ring circuits but have used it when there was an earth fault and you'll find something in the megaohms. This is just to prove that the circuits themselves are wired properly. To look at the house being earthed is more difficult. Check that everything is earthed back to the consumer unit with copper and then follow from the consumer unit backwards. As you are in Texas it may be that the ground itself is not a strong enough Earth at the dpeth that the earth rod has been put. They should have put the earth rod deeper. An alternative is they may have used the plumbing (bad) and I would check to make sure that along the plumbing everything is copper. A former colleague of mine from the US had a house where the plumbing passed through a galvanised tank, thus making the house electrically unsound, easily fixed with a length of copper wire jumped from the inlet pipe to the outlet!