Tire Tech - Tire Size Information
Just do a little math, and you can caluclate the diameter of your wheel + tire and then find the size tire that suits you best.
If you get a set of tires that maintains stock height, and you're upgrading the diameter of the wheel itself, it will actually be kind of hard to maintain the same ride quality. The actual airespace within the tire helps dampen the bumps and jars of driving. It won't feel the same at all, but it's something you get used to after a while.
When you say, "handles best", what kind of performance are you looking for? Wet? Dry? Snow? What kind of tires are you running now and how much money are you looking to spend?
A lot of your questions can be answered right there on tirerack.com. They have really nice surveys and customer reviews you can read and testing that they've done with their tires. It's really helpful and informative.
Howie~