Sorry, I can't help you with the type of grass. But I do have some suggestions that will work with any type.
Don't just leave it dirt. Improve the dirt. Add compost to the soil. If necessary, have the compost roto-tilled in.
Organic matter helps the soil to retain moisture. Periodically aerate the soil (yearly is a good idea if you can do so. A pull-behind aerator is not that expensive if you have a small tractor, and well worth the expense.) After each aeration, add more compost on the surface. Grass with a deep, robust root system can survive a period of no water for longer than otherwise.
You may also find it a good idea to check your soil for problems. Is it heavy clay? Sand? Are there problem trees in the area, like walnut? Is the soil too acidic?
Obviously, the soil needs to be graded away from the house (in the back yard). If that means you need a retaining wall, then you need a retaining wall.
Regarding the swale, improved drainage sounds helpful. The real question is, why isn't water shedding (what is the real issue)? I've had swale issues, and the problem in those cases, was not with my swale, but the neighbors'... so water backed up in my yard. In such a circumstance, you can talk to the neighbors about the issue, ask them to fix it, offer to help, and/or sue them for damages.
But if the neighbors aren't to be blamed, then another alternative to keep the grass cut very short (grass slows drainage). Or you could check into a trench drain (concrete ditch). This is just another option that I didn't see mentioned, although it may not be your best option. As Tester101 pointed out, being there to see the issue is probably necessary.
Regarding power outages, gasoline or propane generators are the most reliable answer. A moderate generator should be enough for a sump pump, the fridge, and should keep the toilet flushing too. As you know, the drawback with a battery bank is that once it discharges, then you don't have a simple solution, like getting more gas.
Edit- Here's a possible way to use a retaining wall to increase the grade away from the house.
Best Answer
I've looked at this in the past. These two links are pretty general, but each has an interesting tidbit.
Link 1 "If your yard has especially shady spots, you might be better off seeding those areas, since most sod is made up of sun-thirsty grass varieties."
Link 2 "A prime disadvantage of sod is the limited number of grass species included in sod mixes."
Other than that, sod is a clear winner if you have more money than time. I've done both, killed both, and revived both...lets just say I'm eyeing my neighbor's lovely rock garden with a bit of envy.