Something I'm amazed never gets mentioned, How much is you life worth? Safety should be a primary consideration here since all the fuel savings in the world won't mean crap if your dead or seriously injured. Since you will be spending so much time on the road, your chances of getting into an accident go up that much more.
Hybrids are good for around town because the regen break, but on the highway, they tend to fall in line with other cars, except they have a smaller engine which helps efficiency.
I have seen some 01-05 Civic hybrids in our area for $3-6K, 40+ MPG in a comfortable, manual trans, very highly rated crash test vehicle that handles well, & with more room than you'd think. If the battery system craps out, you still have a 1.3L Honda engine getting you around.
My wife just drove the Civic from MT to FL in 3 days and was impressed with the comfort of it.
At the end of the year, you've spent $400 more on gas in the Civic compared to a metro, but saved $1,700 from what you'd have spent on a 23mpg car in fuel. Plus the resale value of the Honda will always be something.
Civic Hybrids in FL Craigslist
I love my Civic.